Fix a Car That Runs Rough But No Engine Light - MUST WATCH

[@myRatchets]

Here are links to products which were used in this video: Entry Level Scanner: amzn.to/2mjf7YS Pro Series Scanner: amzn.to/2bXGDp4

[@robb1788]

Good morning, how is it possible to get in contact with you?

[@ibxlegendx]

We should do a video together. I live here in Chula Vista. I have a Jeep Liberty that we can do a video with

[@2wheeladdict12]

D

[@JohnDoe-gk4kn]

My code is ford p0132 and p2197 lean stuck high voltage. Air leak? Or bad 02? When I start cold and drive it randomly will stutter and randomly refuse to accelerate but after its good and hot runs fine. Even when cold if a floor the pedal it takes off no fuel dump issues. I can't find air leak but my filter was dirty and the casket needs to be replaced. Of course its old 2005 123k miles

[@worshipwhilewewait]

HUGE THANKS! Got a 03' S10 4.3 Vortec that's been pulsing when warmed up. Couldn't figure out the problem (no codes) and then (after watching this and using a Autel scanner w/live feed AND NOW UNDERSTANDING what the numbers meant) decided to check the pre-O2 sensor and the pipes leading up to the engine and FOUND A SMALL LEAK. Fixed leak and replaced exhaust seals (donuts) - and FIXED ENGINE! Truck has NEVER ran so smooth and SO DANG QUIET! HUGE THANK YOU - been trying to get this sucka back to the way it used to run when I first bought it back in 03' . Might have took 17 years but DANG!!!!!!!!!!! THANK YOU - got a WHOLE NEW APPRECIATION for people that TEACH!!!

[@mtsarch]

When ever I attempt to DIY I go from a rich condition to a poor condition

[@thalegacy6]

Hahah, awesome! That's how I was before I learned how to actually test things and not use my parts cannon.

[@Imjussaiyanbro]

@@thalegacy6 hello, my truck starts and runs well but after 20 mins running hot the engine runs really really rough and will not drive, can’t figure out what’s causing it.

[@ericwakefield4977]

😂😂

[@mayken6661]

@@Imjussaiyanbro so during open loop, I I would check O2’s , but it could be Many things. Have you figured it out yet? Do you lose coolant?

[@Imjussaiyanbro]

@@mayken6661 to be honest I have given up for the time being I tried working on it for about a month doing the easier things first now I’m just letting it sit in the driveway. A lot of people say fuel pump but haven’t replaced or tested fuel pressure. Don’t know how to check sensors I’ll look it up, no coolant issues, too me it seems like it’s struggling to maintain correct air fuel mixture but what’s thrown me off is that it takes 20 mins to start doing that. Symptoms are shaking of Engine, poor to no acceleration, stalling. Louder, and all around having a heart attack. Seems like a overheating engine from loss of coolant or oil but it’s not that.

[@markcopple2870]

For years, every time I have had a problem with my cars your videos have always come to the rescue! Thank you! You videos are well produced and have excellent content. Thank you for mentoring me through my DIY adventures all these years!!!!

[@JonnyDIY]

Miss u Eman, you busy farming or what? 🤔👍

[@WhiteVolvo]

The amount of uploads since you got back is insane !

[@labradormcgraw]

For a ten minute video, that was actually very comprehensive. Many people could learn a lot from this.

[@supersabrosinho]

Your vids have a great average Joe vibe to them. You're helping us all out. Thanks! I would love to see more electrical diagnostics/repairs if you're into that stuff

[@olbabybeard]

More humble than average I think. Humble Joe vibe

[@rpm172]

You have intelligent, actual content with excellent delivery. Clearly you are highly educated about your industry. Subscribed today and I look forward to playing all your videos

[@markh.6687]

(In Professor Farnsworth's voice) "Good news, everyone! I've come up with a simple explanation for air/fuel ratios! Let me show you four real-time graphs at the same time so your heads explode!" Serious, very concise explanation of what it all means.

[@StationRussification]

Long Term is the window of time the adaptive memory dictates the fuel trim, Short Term is live data calculating to learn the parameters for the adaptive memory to update the Long Term. The O2 sensor signals lean below .45 volts & rich above .45. The Engine Controller only cares about that threshold & uses that to determine fuel trim. .. in other words the computer calculates the % of time that the O2 sensor is past the threshold of .45 volts & does that each time the threshold is crossed.

[@pKammi]

Wow thank you. I ran my engine on idle and the LTFT was 10%. I sprayed some soap water on the hoses and found the vacuum leak. You saved my car bro. Thanks.

[@myRatchets]

Glad it helped

[@crowdsfavorite4660]

Whenever I have rough idle or running conditions without any codes my natural instinct is to check the entire intake/clamps,connections, sensors for the intake and most importantly check that throttle body and give it a nice clean. Any air that is escaping the inlet pipes will trip the vehicle out

[@humbledhands]

Remind me of the homie in Wyoming 👊Over the years you have been making my backwards introduction to doing it yourself a lot easier with these common sense videos with some slick west coast humor! Hope your avacados farm is producing for you and family's well. Happy new year looking forward to any types of vids you decide to make whether about cars or not keep kicking homeboy!

[@jimgordon3206]

Your videos are the most thorough and most clearly explained I’ve seen. Thanks for sharing your vast knowledge.

[@EverydayProjects]

Very Good. I've been a subscriber for years and your videos are getting better and better. Greetings from British Columbia, Canada!

[@johnsee7269]

Esta bien muchacho, ole'! You gonna more to Tennessee like Scotty? You guys are performing a valuable public service. Thanks!

[@T4nkcommander]

Always appreciate your videos. Practical and to the point, while giving enough technical background to satisfy most curious minds.

[@squadman3376]

Thanks Chief !! Brilliant explanation. BTW guys,On V engines, Bank 1 is cylinder 1 side.

[@macknumber9]

Thanx that helps

[@JosephHarlow]

Got a good one for you. I have a 2001 Ford Explorer Sport trac. Mfg date is the first (there were two slightly different models of the 4.0 SOHC is what i've heard, don't know how factual that is). A bit of history - it's necessary and i'm hoping better help you with your video content idea. -Shout out to Joseph Harlow if you do it because of this comment. I don't know why but in my opinion. It would be cool to know something I added fueled your creation. haha ( everything obviously still your intellectual property ) So, 137,000 miles. I bought it at 133,000. First issues were valve covers leaking, had that fixed by professional mechanic. In addition to some suspension maintenance/repairs. I'll stick to engine though for this just to stay focused on the actual problem and difficulty locating the cause/remediating it. The list of engine repairs below are notated in order of symptom - repair symptom: visual inspection determined leaking coolant around the thermo housing - repair: replaced thermo housing. . NOTE: With this and anything i've personally repaired. Has been an absolute nightmare. I believe because it's just never had anything replaced since driving off the lot from original purchase. Long story short, I broke a bolt trying to remove the leaking thermo housing. Took almost a full week in freezing weather to get the fu***** thing out and re-tap the hole. I was able to get a nut and bolt to secure well enough to pass a pressure test. symptom: rough idle at stop and heavy vibrations at low rpm/speeds with slight jerking and whining noises from power steering pump. repair : replaced power steering pump but kept the same pulley. symptom: squeaky belt and/or pulley repair: replaced with a noise reduction/higher performance belt (didn't believe it myself until i experienced it, the more expensive belts DO make a tremendous difference) symptom: still rough idle, getting worse and to the point of almost completely stalled engine if stopped and/or in park/reverse. In addition to low speeds/rpms. If in Neutral and/or driving higher speeds/rpms. The sputtering or hesitation would not be noticeable. Though if i press that accelerator down harder ( not flooring but like if i was to try and pass someone on a 75Mph limit HW) I hear a sort of clacking sound. . .similar to what an exhaust leak would sound like if a manifold would come lose on the block. Like on some of the Dodge rams. Only when accelerating harder than normal though. Normal acceleration doesn't do it. Attempted repairs without resolving: Replaced all spark plugs, spark plug cables, PCV Valve, IAC, O2 sensors (only 3 on my vehicle, 2 downstream and 1 upstream), the 0 ring gaskets on the upper plenum/intake, cleaned the throttle body, new MAF sensor (though i'm still only getting highs of maybe 12 when at 2200 RPMS), DPFE sensor, cleaned the EGR valve (though still couldn't get the valve to open when i had it off the car, not sure if it's supposed to be able to do that even), replaced the radiator (had leaks and the cap was shot), oil change with a new oil filter, new overflow tanks(they also had holes/leaks), my fuel line ended up getting melted on the egr pipe (forgot to move the protective mesh back) so replaced the fuel line. I'm now about to replace the fuel filter and the air filter. I consistently am getting a misfire on cylinder 2 code. Though my friend who is very knowledgeable and experienced with Ford trucks/engines. Has looked over the spark plugs/cables and we even re-crimped the cables we suspected of being faulty. With no change. We found slight air leaks in the upper plenum and have used JB weld (plastic) to repair the small cracks.... At this point as i'm sure many of you are now after reading all of that (sorry for the lengthy comment) have a bit of overwhelming feeing or head is spinning. I'm at a loss, 2 mechanic shops i've taken it too, are at a loss as well. Between the two of them its over 100 years of experience combined.. Last night the cel was actually not on anymore and I hadn't cleared the codes myself so i thought.. maybe it was a clogged fuel injector or something from my replacing the fuel line. Though today again, it starts sputtering/stalling and cel came back on for misfire on cylinder two.. I don't see any arcing or issues with the firing.. it starts up and seems to warm up fine. Then just starts acting as if its going to die. Then put it in reverse and it almost DOES die, though putting it in drive or park will keep it running enough to stable itself and i can put it drive and it drives .. more or less ok .. but pretty shaky vibrations at low speeds.. I guess what i'm getting at for a video is... when there are so many possibilities for the cause.. and i've repaired just about everything i can possibly think of next to just rebuilding the engine. It's doesn't appear to be a lost cause.. both mechanics and my friend all say the engine doesn't appear to be close to seizing up or anything. It's just very frustrating, embarrassing (because I have a stereo in the truck that is 2x what the truck is worth. i would really like to be driving a truck that actually works AND have a nice stereo. haha) Mostly frustrating because I don't have the money or now even trust (one of the mechanics charged me $450 to move my spark plugs at the distributor to the correct firing order (maybe 10 min? ) then did a smoke machine test and said they didnt find anything.. yet i found many areas of air leaks when i picked it up.. AND it was still not driving well... OK i'm done.. If you could use any of this and if it gives you inspiration.. awesome.. if it even sparks an idea for the next area i should be looking. even better. if it helps others NOT go down these rabbit holes , effing amazing. Now that i've taken most of your day by making everyone read all of this, i'll let the process take it's course. Again, would be cool to just have some sort of notification if it does inspire for a future video. Thank you for all that you do!! I only recently subscribed but when in the middle of projects, your videos have helped A LOT!!!. -Kamikaze

[@bretc9644]

Glad you're back on the scene... great video.

[@techsir8866]

If you have a BMW, the front 3 cylinders are bank 1 and the rears 3 cylinders are bank 2. This is very uncommon for the average car but important to those with in line 6 cylinders. I also had a power problem recently with my 8.1, figured out the O2 sensors were bottoming out to 0 mV. The issue did not trip the light but had set a code in the engine control module.

[@peralesadan19]

Hello, I love your videos, they're right to the point and easy to understand. My problem is this, I have a CRV 2012 and every time I start it and drive it, fir the first 5 minutes the car shakes when going from 20 to 40 mph. After a few minutes of driving, this problem dissappears. I checked the #1 sensor and it throws. 02 to -1.5, my LTFT is 12.5% and STFT about 10%. What can be the problem. No check engine lights are displayed. Thank you for your help.

[@abbas2915]

Hi Ratchet , my 2001 Toyota Siena hesitates at low rpm but when i put higher octane fuel in it the problem goes away , the car has 189000 km on it and the check engine light is on , Thanks a million for your great videos.

[@Cityj0hn]

Dear Lord, what a hero! I'm a physics major and I've been going nuts trying to figure out why one of my cars is running so rich it's essentially squirting fuel out the tailpipe. Now I can measure it and troubleshoot it. Heck, you can even find vacuum leaks by spraying fuel around the engine bay and watching the graph change.

[@powerofknowledge7771]

Thanks so much for the info!! I think this may be the problem with my 2010 Chrysler Sebring. It has a rough start, and sometimes a long start. Runs and rides very smooth, but sometimes idles a little rough. I have an OBD2 reader with the Torque app. I'll have to see if I can check those things you mentioned with it.

[@heathergarrity1889]

Hi great video,you know your stuff.I hope you can help me.I have a 2002 mustang gt with only 76,000 miles,and in excellent condition.5 months back I had an slp loud mouth 1 exhaust with an x pipe installed.Iy ran fine for months but slowly developed a shaky idle.Now it is idling rough enough to feel it in your seat.It also makes these little puff sounds while idling, but doesn't make the puff sound for about 3 or 4 minutes when it starts to warm up.After it is warmed up it makes puffing sound every few seconds while idling. Never did it before new exhaust. I was told it is running rich too much fuel and that is why it is making little puffing sounds.Car was hooked up for hours the other day and produced no misfire codes,although there was a code for a downstream oxygen sensor on bank 2.That was fixed but it is still making puffing sound.I was told I need a tune because of x pipe and shotgun resonators I had Installed. They say it is the new exhaust making it run rich and because of xpipe it needs a tune If you had any ideas that would help me alot!Dies this make sense to you.I want to dyno tune and the tuners said they can adjust my levels and get car running again.Thank you.

[@breeve9742]

I’m assuming by now it’s fixed, but with aftermarket exhaust it doesn’t make it richer it can make it leaner (too much air) bc the new exhaust is less restrictive. A tune would be most likely necessary

[@Carlostype]

My recent leaking flexi hose just ahead of the oxygen sensor caused a lean condition and my motor smoked after wot. Diesel engine so no trims to view but the repair fixed issue!

[@StyxYRenegade]

Runs rough but no light? Valve Cover Gasket? This exact thing happened to me and it was an old brittle gasket not sealing perfectly.

[@chaleorta]

🤔

[@markh.6687]

Mechanic once told I blew a seal; I said "Fix the damn thing and leave my private life out of it, ok, pal?!" -- Wet Dream by Kip Addotta.

[@markh.6687]

@@chaleorta The brittle gasket allows air leakage, which affects the Positive Crankcase Ventilation system function also. In turn, depending on the engine design, the 02 sensors start showing a lean (too much oxygen) condition, even though that's not actually true, and tell the engine control computer to reduce the airflow to the engine. So now the throttle body flap (air intake of modern engine) is partially closed off so engine is being somewhat asphyxiated, causing a loss of fuel/air balance as it tries to keep running on less oxygen, leading to rough running.

[@StyxYRenegade]

Mark H. A brittle gasket also can allow oil to seep into the spark plug holes. Which was my case. Originally, I replace the spark plugs which fixed the misfire but only for a month. I the replaced the valve cover gasket, and it fixed it.

[@markh.6687]

@@StyxYRenegade Interesting; never thought of that leak path. :)

[@spelunkerd]

The 'sleeper' I keep forgetting is a stuck open EGR valve. Often not much to point to the diagnosis as a cause for bad idle. Gotta remember to check.

[@w-dad4040]

I think this is the rough/low idle problem I have in my 01 Saturn SL1

[@thromboid]

Great point! Now would that cause a rich condition (due to reduced oxygen in the exhaust or misfires) or a lean condition (due to excess airflow into the engine)?

[@spelunkerd]

@@thromboid It's been a while since I thought about this but I believe the fuel balance is usually not much changed. Scannerdanner did a handful of videos on this topic, and he explained that the recirculating gas is largely inert, neither adding much fuel nor appreciably changing oxygen concentrations. Pros seem to make this diagnosis on the basis of pattern recognition, or maybe trouble codes in more modern cars. Bumpy idle is the clue, improved at higher throttle. So this presents like a vacuum leak without the characteristic WOT improvement of a lean condition as seen with a vacuum leak.

[@davidhammond8098]

Are you going to break down how to find what the actual problem is? I have a 2016 Kia Forte 5 with a intermittent rough idle and no check engine light. Welcome back

[@GeneFever]

Thanks, I learned about fuel trims today and my scanner has live data capability. Also, lol at Beavis and Butthead.

[@donnaeastman4486]

Thanks this helps a lot. My LT fuel trim was moving higher, my car doesn't trip the CEL until 15%, I used some lucas fuel injector cleaner and replaced a cracked hose, that seemed to help. My mechanic recommended putting in 44K once a year. What do you recommend? Lexus RX330 182K miles.

[@keepitsolidkeepitreal2877]

44K AND BERRY’S MAN’S CHEM TOOL INJECTION CLEANING AND RED LINE WORKS GREAT FORD ME 5.0 1989 1998 F150

[@mumbles552]

Great video and explanation but it might be mentioned that the 14.7:1 air-fuel ratio is calculated by weight, not volume, as outboard motor and chainsaw fuel mix is done. So that would be 14.7 lbs of air to one lb of fuel.

[@mckoylach1622]

Great video. When it shows positive numbers,it means,it’s running rich,right? And negative numbers means running lean,right ?

[@kagmath4532]

Hey @ Ratchets And Wrenches I have a terrible experience. I drive 07 Honda CRV 2.0l (Stick/Manual) than lacks power. When I floor it on the road, the car doesn't react to it. But when you pull your leg off the pedal, just before your leg is off the pedal power kicks in. So by deduction, when you lightly touch the pedal, power response. I took the car to a dealer for scanning, first I got a code that AF sensor failure, changed that. They later suspected PCV Valve that was ok. No more codes. Injectors work fine. Fuel pressure ok. Oh, lastly. On the scanner, it showed a bit of lean condition. Where can I go to look next?

[@jajaid6]

Really enjoy his videos,super informative! Glad to see you also had my red autel scanner!

[@fabianbotero1]

hi! i have a fusion 3.0v6 2010 and my oxygen sensors are 0.04v in idle, the short term fuel trim bank 1 and 2 are +0.9-1.0 if i rev it up the oxygen sensors voltage moves up but in idle is stuck in 0.04v (already checked for vaccum and exhaust and there's no leaks. maybe a fuel injector? what you think?

[@120672alexandre]

👋from Brazil, really like your videos( need a beater car when arriving Canada in a few months).

[@RockYouVideos]

I've had good luck with my Actron 200 something or whatever. Live data feed and can also graph.

[@TheRebuilt1]

Lol before OBDIi and techs had to actually figure out what is wrong with car. Great upload and in knowledge transfer

[@maingun07]

Yup. A few years ago, my 74 Chevy truck was running rough. It would intermittently run like crap making me think it was an electrical issue, but every time I'd pull a hard acceleration, it would dog down and nearly die making me think it was a fuel issue, possibly a bad accelerator pump. Confused the hell outta me before I realized that I had two separate issues. It was both electrical and fuel related. My points were fried and the fuel filter was clogged. Duh. When was the last time I did a tuneup? I went to that new Napa in the next town over, but I haven't been down that road in... Oops. Off I go to the parts house. Told the young kid behind the counter what the symptoms were and he said he could pull codes and tell me for sure. I told him it was a 74 Chevy and he says, "No problem" and grabs a box of adapters for his scan tool. I was gonna let him hunt around under the dash for a while, but his boss stopped him before he made it to the door. As I'm walking out with a bag o' parts, I realized that I had no idea where my tube of Malory went to. So I turn around and ask the kid where the points lube is. He just stares at me. "Points lube?" "Yeah," I say, "Y'know, distributor cam lube?" He scratches his head and leads me down an isle. "Hmm, we've got moly lube..." "No, points lube. Silicon based distributor cam lube. It's like dialectic grease except it's made not to get slung off the distributor shaft. It goes between the points and the distributor cam." I'm not sure this kid has ever even _seen_ a distributor. After confusing the kid for another few minutes, his boss saves him again. "Yup. I know what you're talking about, but we haven't carried that for a while now. I only sell a set of points once every month or two." I had to travel 150 miles before I found a town that had any. Had to go to a store that specializes in classic cars. This old timer comes out and I tell him what I want. "Oh, we don't keep that on the shelves anymore." He goes behind the counter, grabs this dusty old cardboard box, and pulls out a tube. It wasn't Malory, but that's okay. I think they went out of business about 10 or 20 years back. $8 later and I'm heading home to do a long overdue tuneup to my truck. I weep for the next generation.

[@markh.6687]

They still do, because even OBD II can be fooled by other problems. Many times the code can't be fixed by firing the Parts Cannon; you need to figure out what's causing the code.

[@TheRebuilt1]

@@markh.6687 understood but before OBDII you had to be on your game to diagnose with minimal comebacks and still be on the gravy train.

[@T4nkcommander]

@@maingun07 To be fair, we deal with the modern just as you did. Old cars are like old computers - there are a few specialists with the knowledge, but the plethora of new machines means most are familiar with what is in active service. Interesting story, tho.

[@markh.6687]

@@TheRebuilt1 Yes you did; you still do today. Lots of SMA work starts with a botched job by "pros" that couldn't or wouldn't be on their game.

[@kdcustoms1272]

Thanks for the video. You may of mentioned it but I missed it. What scanner is that?

[@Splashfun2000]

2011 Kia sorento, no power, no or very slow acceleration, no check engine light, well occasionally comes on codes vary, fuel trims seem acceptable, friend who worked at a Kia dealership said sounded like fuel pump, there is no valve on this to check fuel pressure so I got creative with a setup, while cranking fuel pressure is good but don't know if it is under pressure. My BlueDriver scanner does not show fuel pressure for this vehicle. Interesting item, at idle in park when I rev it up, Ron's go up as you would expect, but out on road in drive, if I punch gas pedal, nothing, maybe a 1/2 sec blip.

[@glendecuir6317]

Thank you. This is the video I've been waiting for I have this problem. No engine light no codes truck stalls, same exact motor as yours so this works out great for me thank you again. Have a blessed day

[@myRatchets]

Glad it helped

[@luis27787]

What was it

[@1970chevy]

? 99 5.7. Had a cylinder 6 major misfire. Only after 51 mph. Disconnected the egr and now I have no p0300 or p0306 codes. All the way to 70 mph havent gone faster yet. Been good for 2 days now. Any issue leaving the egr unplugged. Thats for the helpfull videos. Learned something on stft. Thanks.

[@solwogan5356]

14.7 avocados to 1 part lemon juice. heck yeah.

[@FredTheLutinoCocatiel]

Guaaack

[@solwogan5356]

FREE guack!

[@jhonatanalvarez05]

You're definitely running rich

[@paulwells4203]

Thanks that's the best graphic explanation I've seen showing how the STFT transfers over to the LTFT when the oxygen cell starts to oscillate again. One question: do the downstream oxygen cells oscillate as well or do they show a steady reading when the engine is in the stoichiometric zone and operating normally? Long time subscriber, thanks for all the great info.

[@alwaysinmotion1]

just wondering if you have come across situation where the car is cunning very rich after changing the injector.I took everything off again to make sure i didn't miss anything. Vehicle in question is 2012 chev impala, injectors aren't easy to get to either. Only code I get is for the bank b exhaust cam sensor which has been there for a long time. Eyes burn when you get close to the exhaust, was never like that before the injector change and had to change that because of open circuit on #6. All cylinders firing now but too much fuel.

[@Johnslist]

Nice tutorial on the trims, which I keep reviewing for the PERSISTENT P0171 lean code! I cleaned the MAF sensor with MAF cleaner a couple times, then tried new sensor, it kept returning so I took to shop for vacuum test, he said MAF sensor. I tried another new one, code returned. There really are no symptoms but I was going to test fuel pressure but I don't have a test port and it seemed a pain and I was told it's rare on a Toyota and there are no other idle or performance issues. I'm back to my original MAF sensor and may replace just to get rid of that variable (though two others didn't fix anything). I'm thinking O2 sensor or injectors, but I'm out of ideas.

[@kobo19190]

My engine runs high rpm at start up of engine then low after it warms up and then it also try’s to stall and misfires but I have already changed the egr valve idle air control valve new battery new alternator new spark plugs and wires and also I’ve got a cold for the egr valve that keeps coming back on every time I go to drive but I have a brand new egr valve on there what do I do? Please help

[@hawerddolbee1278]

Reading mathematics equations from a rudimentary computer it must be hard but you make it sound easy.. much thanks great job

[@myRatchets]

You can do it :)

[@billsmith2212]

Great foundation to start a diagnosis . Complete visual under hood , etc. Then scan and read the data . Test before replacing parts !

[@matyasrozsahegyi5818]

Nice video as always. But! What about Diesels without oxygen sensor? How can I diagnose mine? (TDI owner here 😀)

[@thhall459]

Please weigh in on the common Honda S2000 off-idle stumble and low rpm rough running problem that has been discussed ad nauseum on KZbin. I'd love to hear your opinion. Thank you very much!

[@TerminalChillness]

Thank you!!!! I’ve been trying like hell to find info one where to start since my transmission is hard shifting especially before engine fully warms up, but there are no codes. And it’s driving me insane because each hard shift is damaging the parts inside the transmission little by little. So awesome video, very useful ✊🏻

[@MLinktheprophet]

Did you ever get a torque converter code?

[@macknumber9]

Check throttle position sensor. He has a good video on how to check that. That can cause hard shifts sometimes.

[@alanbeggs3172]

Thanks,having this exact issue but worse when stone cold/just after starting.Now i can look at the scanner data with some knowledge. Keep up the great videos!

[@JuanHernandez-ov8wv]

Great video good info as well. What model scanner is that autel u are using that u graft 4 components with.

[@sv_endless6340]

I have a jeep wrangler 3.6 v6 That stalls and jerks some times. NO ERROR codes on diagnostic. How can i figure out what this is on my live data. Car runs and drives good no issues until it cuts or stalls. I then put it in park and then it starts again no issues. sometimes it does not go into drive even when it is in drive it seems like it is still in park. But i think it is because when it stalls i try start it in drive and the computer does not register it immediately i don't know. I saw post where some people had the same issue and replaced the crank position senor and solved it. Any advise PS: Even if i take of the plug while it is idling and the engine stalls and i do diagnostic there is no error code, not even a open short or something.

[@BuggysTowJamBot]

Depending on year of your wrangler, usually the computer needs to see the fault more then one time to set a code and triggering your check engine light.

[@BuggysTowJamBot]

Oh and don't just throw parts at your jeep, either diagnose the fault yourself or pay diagnostic fee. Alot of people think the diagnostic fee isn't worth it. But if you buy crank sensor and that doesn't fix it, then you'll do some searches and purchase another part, and keep wasting money. When you may never find the fault this way, but end up spending more then that original diagnostic fee. If you take it to a mechanic and he doesn't know how to diagnose correctly, and just starts changing parts let him know you could've been a parts changer and you're not paying for things that don't fix your jeep. If he diagnosed it and didn't actually find the fault. Hopefully wherever you live. You have good mechanics who can diagnose your issue and fix it easily.

[@chaleorta]

Take it to south main auto and baam!!

[@pitdecor7619]

Hi I have a rattle noise on start-up on hot or warm engine . That sound goes away after several seconds . It's on 2005 ford e250 4.6 v8 engine. No check engine light . It's weird because I have never experienced that noise on cold start. I know some people have same problem did some research online but did not find any answer. Do you have any suggestions. Thanks .

[@konstantindufnik696]

Actaully I have the same car but its a 2004, it does the same and only has 140k kms, mine only does it after sitting for a while, no idea what it is

[@pitdecor7619]

Van has 214000 miles does not burn any oil, compression is good on all cylinders

[@futureshock7425]

Change your air filter you’d be amazed, also check air intake hose to the throttle body to be sure the rubber hasn’t cracked

[@Switzerlandboy420]

Change air filters spark plug all coil and changed a cracked hose stil vibrate at 600rpm when idle at red light or parked idk if it could be the battery now .. dodge D 17

[@elevatingmindss]

I have a 2007 Toyota sequoia sr5 4x4 4.7l no Check engine light on and rough idle when at a stop and stumbles a bit when put into Is neutral or park the car idol's perfect but when I drive idle slow and rough new spark plugs new plugs oil timing belt water pump Vacuum lines Is fuel injectors cleaned still can't figure this out but makes sense about a lean or rich. Is there supposed to be Pressure in the gas tank when you pull gas cap of on a hot day? I don't ever hear a vacuum on a hot day when removing Gas cap to fill up?. I believe this is where I'm not getting the Fumes delivered to the manifold? 7 months with replacement parts also replaced O2 sensors.

[@jameslaver3339]

What if you have high long term fuel trim (10%) and short term at 5% and the O2 sensor is reading high at 0.78 or thereabouts consistently? Does that mean the O2 sensor is failing? My bank 2 cylinders are carboning up and running rough. Would disconnecting that O2 sensor help diagnose the issue?

[@Erik-rc7iy]

Great video, since scotty is moving out can you move to Texas please?

[@lawrenceanderson6167]

I have a 2001 Honda CRV. recently, when my wife drives the car ( her baby) when she goes to stop for a light or stop sign, it almost stalls out. She has to put it in neutral to keep it going. No check engine light. I was wondering if I should clean the throttle body. Also, how would you check the idle control valve? The distributor is also making noises as though the bearings were going bad

[@carlnikolov]

hey there. my o2 sensor downstream is reading 0.7V or so (2012 honda civic)... and I'm getting worse gas mileage..... short term to long term fuel trim is around 7%...does this mean lean condition? I'm burning more fuel.. or do I have a clogged cat? what should I try first? change the o2 sensor or change the cat? I don't have any vacuum leaks that I know of..

[@TGBPEnglish]

Informative, useful and straightforward. Thank you!

[@WhatsForDinner-h2x]

Extremely informative and explained well. Thank you!

[@inamrehman8709]

I have 2010 toyota corolla 2NZFE , 1.3 L engine, it has continouse long term rich -14% , mechanic checked every thing, 140 PSi dry compression for each cylinder. last he found that there is no thermostate, my question is , running engine without thermostate result in LTFT -14%,? assuming other things working fine

[@GaryTaylorvw]

Hi, can an egr valve cause lean codes? I have a jaguar sv8 4.2, supercharged, I replaced the brake booster seal on the throttle body manifold… as the tube was really loose, I was also getting a p010b, I replaced the maf on the sensor reading crazy air flow… now it runs perfectly, no p010b error.. but still getting lean codes both banks after a long drive, but now the CEL has stopped coming on… I’m still getting cat under threshold every now and then… when I did the booster seat “not the easiest to get to” I took off the throttle body and it was caked up so I polished it all up… but now I’m thinking if that was that bad, then maybe the egr is as well and sticking… fuel trims seem to be within reason driving on the motorway… it’s low rpm when they seem to go high on ltft Any suggestions would be great

[@Milkweed760]

I'm having an issue with my g35 my bank 1 fuel trims are reading high in the positive side, my upstream O2 reads at about .300volts and I think it's my cause for my p0300 code. I did a smoke test today to look for leaks but everything was sealed any ideas on what to look into next

[@abdulgaderalshallwee8881]

Hi My chevy colorado when start car the o2 sensor work good and the fuel trim also good in ideal But when start driving the o2 sensor stop working and stay in 050 mv reading and the fuel trim go to+35% Is the problem in the o2 sensor? And thanks

[@aaronlancaster92]

My 06 cobalt is running lean with a po171 code. It's a 2.2L manual transmission and my stft is 0 and my Ltft is 19.5 can u possibly help me figure out what to do next. I replaced the fuel filter, ran a fuel system cleaner, did oil change, thought I fixed the vacuum Leak. But now I know it's maybe a maf or o2 sensor but I hate chasing. Maybe u can tell from the numbers what it is.

[@rydgomez2]

So I got good trim readings for both short term and long term at idle but at 2500 rpm’s bank one long term goes to -10 %. While bank 2 stays near zero. Would that be a leaky fuel injector. ?

[@stablemods9646]

So I have a 2013 audi a6 3.0t and it runs horrible only when it's below 40 degrees fahrenheit, the engine is loud and it has a good amount of vibration but when it warms up it sounds a lot better but not as good as when warm outside.....also when it's cold outside it makes a vibration when when Depressing the gas slightly while driving (no matter what speed or gear) I guess it would be more of a growling noise. Iv been trying to figure it out but can't find the reason. Also when I'm driving and put the car in neutral and Depress the gas pedal there is no growling noise, so could it be my transmission or is it because there is no load??

[@enriquesoza4842]

Hey hey hey!!! Is good to have you back. Question: Is it a good idea to blow (or vacuum) the air filter once in a while? Thanks in advance. Greetings from Chile

[@myRatchets]

Hi, You have to be very careful if it tares you have done more damage than good. If you have to just gently hit it against something to get the dirt off.

[@libbyjames7981]

hey I got a question what is the best car to buy as an 18 year old first car and insurance?

[@keepitsolidkeepitreal2877]

Truck

[@keepitsolidkeepitreal2877]

Coupe

[@keepitsolidkeepitreal2877]

AAA OR ALL STATE INSURANCE

[@powersww1reset]

Low mileage Toyota anything

[@MissouriOldTimer]

I have a 2006 forester, the problem is , when I come to a stop sign/light sometimes the engine will shutter and sometimes even die,, but will start right back up. There is no check engine light. there had been a check engine light on for quite a while so I took it to a shop and they discovered that someone had put one of those "defowlers" in where the down stream sensor was then put the sensor on top of that. I have heard of that to try to trick the computer, anyway, they took that out and so far the light has stayed off,, it runs great with plenty of power and it idles very smooth. I did put in new plugs and wires also both new o2 sensors, they are the good ones not the cheap ones,, I didn't even notice the gizmo someone had installed when I changed the o2 sensor. so I wonder if you have any idea. I even replaced the maf sensor. thanks. Vernon

[@markkasseybaum5115]

Hi how r u from Australia I drive a Kia Optima 2005 automatic 2.7 after driving for a while or towing a load and motor gets hot I turn car off and then go and start sometimes the idle or RPM go up and down basically over 1000 RPMS and back down to 0 and up and then stalls I’ve disconnected the idle control valve but does it when disconnected so I don’t think it’s idle control valve any idea 💡 thanks

[@infinitig3549]

My short and long fuel trim it’s reading 0% you think it’s the o2 sensor bad ? I already checked mass tps sensor and injectors and I don’t wanna just change the o2 sensor and end up being not the problem because they not cheap

[@johnrolandgabagat9129]

Sorry not quite understand this. Can you walk through me ? I have -20 and -20 short term and longterm fuel trim? What parts will be check ?

[@Markangler80]

Loving your vids in Australia mate👍

[@NunYaBeezWax80]

My Eco mustang when running on stock tune is 14.0 AFR on idle and can drop to 9.4 AFR on WOT. On my tune it used to runs at 14.7 AFR on idle and 10.8 in WOT. Its has 84k. On the tune it used to run at 12.5 and stock was 11.7. It has been a slow but gradual loss. Piston compression on all cylinders are 130 psi. Have not check yet for fuel trims on my Launch 129x scanner. What are your thoughts before I dive in any deeper. Could be an injector stuck open.

[@Xmaxadventures]

Do you know what would cause an idle to stay at 1200rpm until a complete stop the 800. It is a manual I even tried putting in neutral an letter clutch out still stays at 1200 until stopped.

[@MPEREZZ143]

Gracias por tu tiempo que pones en todos tus videos ..

[@jamesschmiechen5684]

I have a 2006 chevy trailblazer 4.2L I got a check engine code P0449 & I've changed the evap control Ceylan oid & the charcoal box. It still keeps throwing the same code, also won't start, will start, won't start, will start. Any advice would be GREATLY APPRECIATED. Thank you

[@nmaniacos]

Short fuel trim is perfect but long is around negative 10%. Any idea what could cause it? The upstream sensor seems to work perfectly but the downstream shows 0.75 volts at operating temperature. Is it possible that the ecu reads the downstream sensor to calculate the long fuel trim? Any ideas how to debug this?

[@Giorobot]

99% your car is running at its peak LTFT job is to keep STFT at zero ,but they isolate 2,3,5 %over and under zero example when there's a vaccum leak (unmeter air ) the STFT will react right away to keep the fuel mixture right, then slowly the LTFT will start going up bringing the STFT to zero but the LTFT will run the way until you find leak and your downstream is ment to run at .450 millivolts but no car runs the way so just reset fuel trims and check again

[@nmaniacos]

@@Giorobot Thanks for your advice. I make reset very often but this doesn't seem to change anything. I can guarantee that there is no vacuum leak. Also recently I changed MAF sensor and spark plugs, without any difference. What i don't understand is why the downstream doesn't follow the upstream. Could it be exchaust leak between the 2 sensors?

[@juanccy]

Your LTFT is NEGATIVE so you're running rich, not lean.

[@Giorobot]

@@nmaniacossorry for my delay I just see your reply .ok your downstream its ment to run on a steady line at .450 millivolts not to isolate like an upstream one so if it's on .750 it's good so you right that there's no vaccum leak otherwise your LFT would be over 10% positive Two questions what's the RPMS at idle? and what car you working on?

[@Steelhorse-enthusiast]

My short and long fuel trims look okay the short is close to 0 doesn’t go + or - over 5 the long term is around the +2.0 o2s11 is bouncing around 0.050 up and down around there which is lean right ? Doesn’t go over 0.0130 the Symptoms I have are while driving it keeps pulling back like I lose throttle response I have to pump it to get the power back I’m lost on what it could be as I have no engine codes or pending codes I have a 2.0 turbo petrol the frp(kpa) sits around 4800 - 4900 at idle and does increase with throttle I put it in gear and put some load on it numbers didn’t drop I don’t no what the specs are for my car a4 b7 2.0 tfsi

[@michaelbaskinmichael9862]

My Silverado is adding 40 parts fuel why I looked air leaks and nothing changed intake manifold everything I know but under load misfires stumbles runs rough to much fuel . Maf low and O2 low voltage. Thanks alot

[@egafx]

hi there, I got my car low idle rpm when cold and high idle rpm when hot. idle control valve and all sensors are new.. I suspect it's my ecu just to old and maybe burnt (common problem with my car), but I also think: is it possible that somehow my ac idle up in-out hoses are installed incorrectly? it doesn't have obd ports.. thank you

[@tvwatcher9291]

Thank you for that! Great video and very helpful!

[@ryanramlochan1504]

Do you have any knowledge of understanding fuel trims on a launch x431 diagun iv,I don't seem to understand it

[@w-dad4040]

Hmmm 2001 Saturn SL1 SOHC, -13% fuel trim total I thought for sure I would have a lean condition due to the factory intake manifold gasket failures. But the numbers suggest richness. Maybe cuz its cold out. Darn this thing is finnicky

[@marcasswellbmd6922]

So if I go with a slightly bigger turbo which will move more air will I have to get my car retuned? I won't be able to keep the same map or will it just keep making the same power but easier?

[@rinorgucati5128]

hi i did a dyno on my car hes advertised to have 204hp and in dyno it made 155 (no engine light ) after that i found the hose after maf sensor was broken but didnt dyno after , could it be that the problem? or something else? thank you

[@blacksheeprc8113]

Hey man I got a question to see if you can help me out with this I got a 2019 Volkswagen Passat it's still under warranty so I didn't want to put the APR stage 2 one tune on this one like I had on my other one so I got a TDI tuning box from UK I got a pedal Commander I got turbo muffler delete I got three inch down pipe thing ran pretty good for only being a tuner bucks like it ran really good for a long time but then it started doing this acting funny like one getting power so I thought it was my pedal Commander acting up cuz I shut it off and it seemed act right left that off for a while and it started doing acting a little funny again so I shut the Pat the TDI box off too and I thought it first it was running better too but it wasn't long story short I'm either thinking I got a vacuum line blowed off or something and when it's when it's kicking in because when it's kicking in the boost if I'm going to hire gear like I'm in town it runs fine if I get out and open road and kick it down dirt every year from so that shift I lose boost I have to throw hit it again instant boost again I f****** it takes off like a rocket but once I get going again and the fifth year or 6th gear as soon as I hit it my car is getting an overboost signal apparently or something that's getting too much boost for some reason and then it's telling obviously the O2 sensor is telling the fuel injection so I don't know if what's going on I can't seem to find the vacuum line yet I even know to pull them off yet and actually check them but that's my next step so if anything you tell me helps me I don't know if it's I really don't think it's the box or the other thing I think it's honestly the car or something to do it's something to do with either because it's got confused do I need to reset the car somehow and what's the cure for if I put all the TDI stuff back on it that is not going over boost it again tonight when I have my APR stage turn on my Jetta I never had nothing blow off thing rain like a tank all the time nothing like this but this one I don't know 2019 32,000 miles on it things brand new oh and the other thing it does when I'm sitting in park and I if I rev it up the only three grand and neutral and I ain't really I ain't revenue right before it gets back to idol you're here somebody else said it was the injectors tapping when they come down from the high river or whatever but other people said the name other people saying this other stuff so I don't know what the hell that is either is my turbo click and tapping around or is that normal or

[@potterg04]

Great video on rough idle, long and short term fuel trims Thanks for sharing 👍 😊

[@2bnax]

MY O2B1S1 ON MY 2014 SENTRA IS CONSTANTLY AT 2.2V DOES THAT INDICATE A MALFUNCTION??? ALSO, MY O2B1S2 IS USUALLY AT .28 OR .26V ?

[@naseerp313]

How long will take to active oxygen sensor after cold start ?

[@ast5515]

In 100° heat, 1 minute. In -40°, possibly 15 of driving or 30-40 minutes of idling. Also depends if the O2 sensor is heated or not. Or how close it is to the exhaust manifold. Short answer is, it's impossible to say. Wait until the coolant temp gauge is in the middle, you should be fine after that.

[@kenya2012asia]

Thanks for your useful video. My problem is STFT is almost 0% at idle but at higher rev range over 2-3000 rpm, STFT will be a positive 10-20%. On the other hand, LTFT is a negative 24%. How can STFT is a positive and LTFT can be a negative? Also, STFT % increase per the rev RPM is normal or some issue ?

[@9thgensi227]

+20 ltft and -24 stft = -4 live fuel trim

[@paquesepas6696]

Hey ratchets, got a 2004 Honda element no code map engine but at idle in the morning and when motor is warm, I'm getting around negative 15 both short term and long term. It smells of exhaust gasses quite heavily but engine doesn't run rough at all and only symptom I'm having is I feel I should have more power. Have new oem air fuel sensor and the rear o2 as well. All my live data looks normal like map, ect, ait, etc. Do you think since these engines need to have their valves adjusted and it's a new to me car with 160k, that valves being out of adjustment can cause a rich condition? Thank you.