Causes of lean condition trouble codes P0171, P0174 - GM 5 3L

[@roadkill5333]

I love coming back and re-watching these videos, even after watching other vids, to see if I absorbed any of the info, and can process it in a real world scenario!! Plus, they are just entertaining to say the least!! I can't do much in the way of auto exchanges any longer, I was really into being "PARTS CHANGER", in my youth!! I did my own parts changing for my own vehicle, and some family and friends, but never knew how much I DIDNT KNOW, until MR. PAUL DANNER, and his real world hands on diagnostics approach!! Let me just say that I'm not a paid spokesman for the ScannerDanner teach-a-tech series, but....... I'm not against drawing in some royalties!!! :-D :-D :-D let me tell you where to send the check!!

[@ScannerDanner]

thanks so much my friend

[@ScannerDanner]

check is in the mail :-)

[@roadkill5333]

ScannerDanner!, headed to the mailbox, right now, to await its arrival!!! :-)

[@KTHKUHNKK]

roadkill5333 Tomorrow I will go to work on my PO174 code on my 2000 GMC Sierra 4.8

[@rdvemo]

Z

[@YouTube.TOM.A]

I can never figure out how I can watch this video two years ago and look at it again today when I am much more informed, and still find a bunch of new information that I can learn from the tutorial. Thank you sir.

[@mikeoneill7360]

I'm 52 years old and find this to be fascinating....You did a really nice explaining everything in this informative video, thanks.....

[@ScannerDanner]

Thanks so much Mike!

[@davidcarney7555]

@@ScannerDanner p

[@richardr5013]

Much more than a mechanic, this guy is an engineer and has very in depth knowledge of internal combustion engines. When you can't figure out stuff, he's the man. Great job Paul, Thank You for your help

[@paulmullins5425]

Awesome video and I used to think these problems were so hard to troubleshoot but not anymore. Man you're a great teacher. Love how you break the problem down and make it simpler. Keep up the good work

[@rexluongo6470]

My grandfather used to pour tranny fluid in the carb or throttle body. Said it cleaned up the system like seafoam, before we knew about seafoam. Used to smoke like crazy. Don't know if it worked but if he did it, it probably worked. He was a rocket scientist, literally.

[@jimbuford4147]

Great video. I always like your willingness to go the extra mile to be 100% on diagnosis and help your viewers get the most out of your videos.

[@homeehsan7007]

Amazing piece of detailed information about fuel trims and lean condition. He has the quality of teaching those concepts to anyone. There are very few people who have knowledge and can convey to other people So SIMPLY IT IS BEST

[@mikevonkleist6767]

How long have been doing this? I've been at this for 37 years. You're one of the few people that knows what's up and why. You think like I do.You're a good tech, dude. Thank you from all of us.

[@ScannerDanner]

About 25 years and I've been teaching at a technical college for 17. Thanks so much!

[@mikeoneill7360]

I’m watching this video again 6 years later from the last time, awesome….

[@zeej5003]

Danner! I just diagnosed a 2013 Chevy Express that P0174 and P0172 lean codes for both banks. (it ended up being a bad MAF). Fuel trims were normal at idle, but on acceleration the long term fuel trims would go lean at over +20%. I could also hear the engine knocking on acceleration with the doghouse removed. The engine also lacked power and the trans shifted poorly. You NAILED it at the end of the video with your comment about lean on acceleration is likely MAF or fuel pump. I spent hours today doing diagnosis. I finally tried a known good MAF and fuel trims went normal, power was back, no more knocking, and trans shifted properly. I learned to use a Snapon scan tool and scope from your videos 10 years ago. THANK YOU.

[@ScannerDanner]

That's awesome, way to stick with it and nice find. Thank you!

[@alansanchez-cp5lx]

What brand maf sensor did you get? I got local autozone but told to go to oreillys but don’t know of a particular brand if you could point in brand direction would help! I am having these issues but to the contrary my engine runs great when cold but when warm weather or engine warms up then i get the knocking or rattling on acceleration and sluggish acceleration and poor shifting… i already replaced fuel pump for different symptoms last year and maf sensor to tackle this p0171 but thinking of buying again this time from oreillys… any help would be appreciated

[@zeej5003]

@@alansanchez-cp5lx OEM (A/C Delco)

[@alansanchez-cp5lx]

Same exact problem here unfortunately i went with autozone as well but ppl tell me to get an oreillys one but idk if it could be an intake manifold gasket leak or maf… i get the p0174 maf sensor already replaced and cleared and came back on after a couple of months…. Same as yours great in the cold but once it gets hot i hear the rattling upon acceleration and truck is very slugish

[@AT_Eng]

this video was posted back in 2016, and still helping me. Great work

[@Juise187]

Subbed at the moment you demonstrated the water test. That was just genius. Your thorough knowledge and process is top notch. I will continue to watch what you have.

[@ScannerDanner]

Thank you and welcome!

[@larrycourtney9117]

I've always used carb cleaner to pinpoint leaks. Put the red straw on the carb cleaner and hit the exact area you're wanting to you will pinpoint where your leak is it will rev up the engine if it's leaking you can also check the O-rings are leaking by squirting them directly. And as far as cleaning the tops of the Pistons we used to bring up the idle and slowly pour transmission fluid into it. It also gets rid of any mosquitoes for miles!

[@stevenbellll]

THANK YOU SO MUCH! In your videos, you have taught me so much. You're not just posting guess videos. You're slick. You just fixed my Tahoe! Again, thank you so much.

[@ScannerDanner]

Happy to help! Thank you!

[@DG-america]

Although I dont understand what you are reading on the screen during diagnostics, you did explain well enough for me to understand what you were getting at. I'm here bc of a 171, 174 code that occurred during load. At least the light was thrown after being parked at idle for an hour in the middle of a trip. Thank you very much for giving me a direction to go in.

[@ScannerDanner]

Yes sir. Toward the MAF or fuel pressure would be my top two for under load lean conditions

[@alexandergonzalez2232]

Doctor scanner Danner! the word doctor means educator and one who studies complex in-balances in 5 different systems and makes a primary and secondary diagnosis. I keep repeating your videos in the hopes I catch one third of your 150%. God Bless and thanks for empowering the John does of the world.

[@Bowhunter-ft8cn]

Thank you for the details in this video. I have been searching ways to diagnose this and never understood the fuel trims and how to use them to help diagnose the issue. Never heard of the water bottle test neither and by golly it did exactly what the vehicle in the video did as soon as the water hit the intake manifold gasket area. I previously tried this with brake cleaner with engine cold as a friend suggested and got nothing. The water gave results immediately. Thanks again for the details given and the tips on how to use the data on the scanner to help diagnose. It really helped me to get a better understanding and I now need to replace my intake manifold gasket. Wouldn't have figured it out without your help.

[@ScannerDanner]

Best comment of the day! Thank you so much and nice job following along. That is credit to you. Not everyone is willing to understand this stuff

[@MoaByte-v2z]

That water trick showed me the same problem with GF's 2003 5.3. white smoke appeared in the exhaust! Thank you so much.

[@stevenmullins9430]

Hands down the best automotive teacher I've come across, and I've seen several. Please keep up the good work

[@ScannerDanner]

Thank you so much! Happy New Year

[@davesministry7789]

Another excellent diagnosis job. So much better than grunt work part changing. I was surprised how much smoke leaked out with this small leak. Thank you..

[@codyfryer1003]

One of the most detailed videos ive come across on the LS engine. Thank you sir

[@ScannerDanner]

Glad you enjoyed it!

[@shaffer4220]

This guy is good. My dad used to remove carbon from the pistons/cylinders by slowly dripping water from a turkey baster into the carburetors. Also, if the ole Holley carb got sone dirt he revved the engine and then quickly covered the top of the carb with his hand to clear the obstruction.

[@northernpatriot9078]

rewatch : thank you!! the correlation between the fuel trims and the suspect intake leak was awesome and finding it with water once you showed that to the customer the job is sold

[@SteveRobReviews]

Paul my 02 chev 6 liter never had a code and only concern was a stumble on cold start. Once in closed loop trims were fine. I was chasing IAC until I smoked the intake and both banks were pouring out smoke at cold. Engine never exhibited any drivability until the temperature went below freezing. I like the water bottle idea a use it . Nice vid 👍👍

[@michaelagalasso2389]

Paul, Another great case study. I have two of these trucks. One with a 5.3 L and one with a 6.0 L this video will go into the archives. I always learn something new from you. Thanks

[@JohnnyMacTahoe]

Had the exact same codes on my 2000 Silverado 327. (5.3) Cleaned the mass airflow sensor... no more bogging or missing - runs like new - no more codes - no more trouble light.

[@devonjefferson982]

Johnny Mac I hope that's my problem!

[@JohnnyMacTahoe]

Yea, hope so. It's certainly worth trying first because it's cheap and easy. They make a spray cleaner specifically for the MAS, use that. Best of luck.

[@codymcfadden8856]

327?

[@JohnnyMacTahoe]

327 cubic inch. That's American for 5.3 liter

[@kklg911904]

Its 323 cubic inches not 327

[@LynxStarAuto]

The water into the carb is a real thing. I witnessed my dad do it many a times when I was growing up. Clears the carbon right out. Especially useful on later emission dressed carb engines which would gunk up the intake manifold, and valves.

[@carylamari6546]

Thanks, I was leaning toward a vacuum leak on my 06 Silverado 5.3 had a PO 171 code and your video confirmed it, I had a 17% Long term fuel trim and a 0-3 % short term fuel trim. when I raised the RPM to 2500 the short term and long term FT went down a little and when it warmed up it also got a little better down to 15% so I guessed I had a small intake leak as it got better as it warmed up and I noticed better trim when cold as I raised the RPM. I smoked the engine from the intake and after the motor got good and smoked I saw smoke coming from under the intake so that confirmed the leak. I will be installing a new Fel Pro intake gasket and while I am there new knock sensors. From the video's I have seen I need to clean the valley and build a silicon U shaped dam in front of the Knock Sensors. Thanks for the Video Good stuff!

[@MorbidXTC]

Ran across this video after getting these codes on my 04 suburban with 5.3. water bottle trick definitely helped test the intake manifold gasket and my engine got rougher and steam did come out the exhaust. On cold starts I had noticed a rough kind of idle until warmed up for a little bit but no codes.. no clue... Warmed up and no problem til the codes today leaving work. Thank you for the simple test trick!

[@ScannerDanner]

Glad it helped! Thanks for the comment

[@ahmedhamoda2995]

just thank you very much indeed scanner danner,, because of you i got my life back to me,, i started a new career and with your helpful videos am taking it forward step by step to successful man, you know only if i were living in the united states i wont miss your classes for the world, A REAL BIG APPRECIATION

[@ScannerDanner]

+Ahmed Hamoda that is awesome to hear the impact of this channel on your life. I am blessed to know this. Thank you!

[@geekdiymechanic4539]

Great video. I like when you think out loud. It allows me to follow your train of thought. Thanks for doing the video.

[@ScannerDanner]

+GeekDIY Mechanic thank you

[@frugalprepper]

I love the water trick. With no smoke machine I have been watching fuel trims while putting some propane or brake cleand down around the intake and seeing if they correct. It always a little nerve wracking to introduce a cloud of explosive fuel around a running engine though. Water seems like it may be a safer way!

[@a2z_farm]

Wow you Are so awesome. Older video. But your layout of fuel trims,....water bottle testing, full functionality of the scanner is so profound in the layout process. This is why i continue to always come back to your videos... im dealing with po161,171,164 right now. 2000 suburban 5.3. 8.5 mpg right now Be Blessed Richard Iowa

[@ScannerDanner]

Define the codes for me. Thanks! I know what the 171 is

[@goenitzlopez9391]

hay paul, I want to thank you for all your teachings, I've recently utilized 2 techniques learned from you. First one was I finished an engine swap on a nissan 360z, and after finishing hooking everything back up the engine would crank properly but backfire and would not start at all. Similar to a distributor out of time, of course this engine is COP. Turns out I had incorrectly hooked up 2 coils per bank. I had the cables reversed, and I came to that conclusion from a video I had seen from you before. I caught my own mistake. Second one just today, 2003 ford focus 2.0 DOHC, engine would stall out immediately when you would press the GAS pedal while in drive. If you revd the engine while in Park, neutral, or reverse (you could reverse fine) the engine would run fine. put it in any forward gear and it would idle fine, as soon as you hit the pedal it would immediately stall out, no chance to do anything, no real chance to even look at any live data. There were no trouble codes. I tried unplugging the tps, no dice, maf, engine wouldnt run with the maf unplugged, no backup strategy without maf, I then unplugged the upstream oxygen sensor, and whaddya know, engine ran fine (with the check engine light on of course). New O2 sensor and the car is now fixed. Thank you for teachings paul

[@ScannerDanner]

+Goenitz Lopez thanks man!

[@joginderdeol1109]

Best teacher best guy best technician. Way off explanation is easy to understand hats off thanks

[@nzkgb1486]

Nice one Paul. Liked the format good to see a person when they are taking to you. I fixed an early 2000 cvic that would run on & ping because of carbon with that water trick no problem just dropped the exhaust at the manifold.

[@SchrodingersBox]

I've pretty much by now come to the conclusion that when these symptoms are described and i see the freeze frame indicating cold misfires and high trims in open loop, i start with assumption of intake leak first and try to eliminate that variable while the engine is cold rather than warm it up like I usually do. I've had several times where trims were zero'd when engine was warm but if vehicle sits overnight, it wont even start for several tries because the leak was so bad.

[@ScannerDanner]

exactly my friend

[@williamarnold958]

i dont under stand why techs dont use a vacuum gauge.thats what the old days techs use when they didnt have all the fancy scanners,i think if the techs or diys use the vac gauge with the scanners that would help solve problems.

[@yusuihang]

Regarding not using vac gauge to look for vacuum leak, I wonder why you would not just look at the scanner as most cars report the intake manifold vacuum as a live data on OBD. Yet, I've never see anyone advising to check this data point when trying to pinpoint lean condition. Is there a reason why this is not a legitimate test?

[@CarShed68]

i think isnt good idea to test vacum or read MAP senssor data,because problem is in mixture not in vacum,vac reading can be same as with vacum leak or without vac leak,if there isnt mega big vac leak leak and idle will be high :) imho

[@SchrodingersBox]

CarShed68 Carshed, you are entitled to your opinion, but not to a difference in the factual operation of a computer controlled fuel system. MAP data is integral to determining if the MAP is the cause of an issue or the result of an issue. Proper understanding of the input parameters for the PCM is the best way to determine etiology. To say it is not a good idea to gather crucial data relative to the PCM outputs is a horrible misstatement.

[@dainbramage8608]

Thank you for making this video . I really appreciate you taking the time to do so . I am so impressed with your knowledge. I have a lean code and honestly it’s kind of fun trying to figure out what’s wrong . Thanks to the wonderful people like you that put videos on KZbin. I can be a jack of all trades , master of none lol .

[@ScannerDanner]

Glad it was helpful!

[@jptrustno1]

This guy is good, really really good. He teaches students, and he knows how to use the snapon scanners probly better than anyone else that i know and i been doing this for 20+ years and i STILL cant do half the stuff my modis edge offers.

[@charleswittmer2477]

this is what IBM would call a specialists in a certain area. not a normal mechanic. now, if his hands are correctly connected to his brain? some instructors can barely hold a tool.

[@jenniferflor2264]

Thanks ScannerDanner! We tried the water squirting trick on our 2004 Suburban and nearly killed the engine. I think we found our problem ;)

[@92camaro100]

Thank you,may GOD bless you, because you just gave me and alot of people vital information on where to begin and check gaskets with water,i never new that,i always seen people check with carburetor cleaner.

[@reneserrano8147]

You are amazing, thank you for all the information, I have a Chevy pick up with a misfire code, this video explains a lot. Thank you again.

[@nathanzupancic6528]

Thanks for the video! Trying to diagnose the 0171, 0174, and an 0101 code on my truck for emissions testing. When the engine is hot at idle I am getting near zero trim numbers and between 10-19% when hot at highway speeds. Like your truck, my code set at 143* or so. This makes me far more confident that I can fix this issue!

[@ScannerDannerPremium]

+Nathan Zupancic cool man, sounds like your issue too

[@jjones9290]

No words! I've said it b4 but can't say enough! Paul you're the best! You truly have a gift for teaching technical skills! I watched this video because somehow I've missed it b4 and I suspected I have these exact issues and same causes on a vehicle and just wanted to test my knowledge. I remembered and would've approached all these issues just like you did! I have learned more from you in your videos than in tech certifications, books and anyone else and I'm stoked that it's coming naturally to me at this point now! Thank you once again!!!

[@ScannerDanner]

how awesome to hear! Are you a premium member? You have the right mentality to be someone who would benefit greatly from the classes. Either way, I am glad you are here! Thank you so much

[@jjones9290]

@@ScannerDanner I just bought your book, started premium and am getting e book also! Stoked to dig into your materials even though your you tube videos are superb and have taught me so much already! Also I praise the Most High for your generosity and willingness to share your faith through this channel! Much love and blessings brother! Thank you for your dedication and sacrifice! I hope it's rewarding you and yours greatly at this point!!

[@ScannerDanner]

@@jjones9290 Thank you so much! I just did a podcast last night and it was centralized around forgiveness. Do you follow me on Facebook too? When it gets released I always let the community know. I'll post it here too on KZbin on the community page.

[@nfotabongconrad3564]

Oh man... You're so dedicated to teach us Scanner Danner. Taking some extra of your time just so we can see on our own what is actually going on. We can't thank you enough... I mean... you're such a great person before being an awesome instructor.

[@Sandbag1300]

Outstanding diagnostic video. As good as you ebook! Really enjoyed watching the Snap-On smoke machine work. Mostly because it was a Snap-On.

[@calimesacox]

32 years Heavy line for the first 12... Went to Aftermarket independent shop and started doing Diagnostics and I am in a love hate relationship with vehicles.

[@W.Khairi]

ScannerDanner at the top of the game as usual, Thank you very much.

[@armandomrgl85]

Great video, I have a 2001 Chevy Suburban k1500 5.3L as I was driving from a long trip on the freeway all of a sudden I started losing power & felt like it was going to shut off, I pulled over the engine idled fine, I turned it off for a few minutes & it starred right up. I drove it home then hooked up my obd2 scanner & got p0171 & p0174 codes, then after a while the check engine light came on. I put in a new fuel filter a few months before any of these symtoms started happening just as maintenance since it had never been changed, It starts up within seconds even when the engine is cold. I cleaned the maf sensor reconditioned the K&N FIPK filter & reoiled it with K&N oil, checked for exhaust leaks, put water around the intake manifolds, but didn't find or hear anything out of the ordinary. I thought maybe I had bad fuel so drove it close to empty & put new fuel in. When driving it feels like it's lacking power, at times while on the freeway it starts shuttering, kind of like when you get a misfire, but it doesn't misfire. I will watch your video a few more times to make sure I understand everything. Thanks in advance for any help if you're able to answer my question.

[@slayer91340]

armandomrgl85 how old is your fuel pump?

[@armando8540]

Robert Contreras I've never replaced it, so it's probably the original fuel pump. I bought the Suburban when it had 38,000 miles

[@thelazyhandyman]

Thanks man. This is definitely something that will point me to the right direction. Very well explained.

[@robqcmccullum8797]

Yes when I started as a Tech working for Cadillac and Olds on HT4100 V8 we would use top engine cleaner and pore water down the throttle body to clean carbon and also soak the top with some of that solution for awhile and start it up later,nice work

[@Baby_j_GodsSoulja]

Woooowww, great video, I just got thee PO171 code on my 2001 Chevy Tahoe, 5.3 liter 2x4 With 251,000 miles. I believe it’s thee original intake manifold gaskets... perfect timing. Because my knock sensors need to be replaced to. I have both codes also for those. Thanks a lot for thee info. Going to do the water test ASAP. 😎👍

[@mission-fishin24]

Paul this was a very informative video. Thank you for the instruction and thorough explanations. That water test was a trick I didn't know. Great procedures for this scenario.

[@Dad19676]

i have the same problem with my chevy tahoe. You gave me hope for tomorrow. explained very well. can't wait to try the water test.. thank you

[@ScannerDanner]

Let me know what you find!

[@mrexecutive1]

Thanks for walking us through your thinking process.

[@sergiozarzoza6926]

Te felicito por tu diagnostico, eso es el código del p0171 p0174 en Chevy

[@austinbachurski5452]

Done piles of these, always recommend going back with the FelPro PermaDry PLUS gaskets, much better design, never have another problem after putting those gaskets in. Plastic factory gaskets are crap.

[@nathanielbolden5053]

Do you need to apply permatex on these gaskets?...im changing the valve cover gaskets on my 10 Buick Lacrosse 3.0L

[@cartoonist1975]

No!

[@PRSQUAD88]

Very nice job I like seeing videos like this showing people the little tricks and stuff showing people how to do it yourself you don't need expensive tools to do it

[@Magnacharger07]

I like the water bottle test it's a good one. My silverado had the intake leak but would run great cold once warmed up would surge and hesitate. Intake gaskets cured it.

[@Forests444]

It runs good cold once warmed up?😂😂😂 😂

[@wyattoneable]

Good call on the fix and excellent visual with the smoke machine. Thank you for taking the time to show us that. This must be common because my 5.7 had such a bad leak water got into the engine.

[@freddysoto6584]

Great diagnostics as always. Thanks for sharing your knowledge with everyone..

[@kristhomas6474]

Nice. Love the water test. Better than spraying brake clean all over. To show the roughness created put a 1/2 full bottle of water on top of the beauty cap

[@jessevp2348]

Thank you for making these videos like how you explain everything and show on screen the scanner.

[@erickrgarcia]

Very good video! Thanks for the tips on checking for possible air leak trouble shooting.

[@0514april]

I think I like you personally. The knowledge is great too.

[@juanar6233]

Love using the water test for vacuum leaks.

[@chrisday4885]

Great info, tons of knowledge and knowhow ! And I really loved the birds in the back ground 🐦 Thanks...

[@clintgray8976]

Outstanding! Very thorough and explanatory in your troubleshooting methodology. 👍

[@17Shkurt2008Pavarsia]

If you have cleaned the mass air flow sensor, checked your evap and vacuum lines and the P0171 code is still coming on, try throwing some injector cleaner in your gas tank because that code can come up from a clogged fuel filter, fuel pump, high pressure fuel regulator or dirty injectors too. I threw 2 bottles of injector cleaners at 2 full tanks of gas and it fixed the code for me. 2005 MK4 Volkswagen Jetta 2.0L

[@eddiemartinez265]

Hey paul jim posted a new video glad to see him back love this one great job.

[@brycethoreson9216]

I would love to be your apprentice. I would learn so much more than I am at my shop. We're told "here is a diag you've never done before, figure it out in an hour by yourself, good luck"

[@ScannerDanner]

well you certainly can be my apprentice remotely :-) I also have a premium channel that invites you into my classroom if you are interested www.scannerdanner.com/join-scannerdanner-premium.html Hope to see you there!

[@SaqibKhaliq]

I learnt something today. Thanks Paul, keep up the good work 😀

[@jesusvaldes4664]

Subscribed right after this video I’ll keep you updated on the condition of my 04 1500 Silverado.

[@ScannerDanner]

Thank you! Looking forward to hearing if your truck has an intake gasket leak or not

[@lucianlucian9911]

A cool video, as usual! Ha ha, that part when you poured water on the intake manifold and the tail pipe started to make smoke circles was pretty funny.

[@splash5974]

I like how the exhaust is sending SOS signals! I've used the water down the carb trick many times over the yrs...my grandfather taught me that one. Great vid! Although you like the water for the intake, i think a propane bottle or ether is cooler😃

[@ScannerDanner]

Until you get an intake backfire and catch a customers engine on fire while they are watching lol Yes, it happened to me

[@splash5974]

@@ScannerDanner Hahaha, good point. I only attempted it once, and it was on one of my own cars(85 IrocZ) Love watching your vids man, your one of the best here on KZbin! Merry Christmas!

[@jimjimm370]

Damn you're long winded Thanks for that

[@wysetech2000]

Another outstanding diagnostic video, Paul.

[@terf7020]

wow, this is a great, informative video. Earns a ranking of Super Duper on the terf scale. Thanks for taking the time to post it.

[@dewaynemoody2024]

Got a front rocker arm cover gasket leak and a intake manifold leak. First time doing an intake but I have my factory service manual. So I should be good to go .

[@CatsMeowington]

I used my HF Z11 scanner to get the P0174. Then found the vacuum leak at the first joint along the brake booster, small split on the end. Tapped it up neatly and applied some heat gun (HF again) to make sure the tape adhesive bound good. Drove as usually and the 174 went away. 2005 VW Jetta GLI 1.8T chipped. Enjoy your thoroughness.

[@hallz9117]

tightened mine up, runs great now !!!!!!!!! THANKS BROTHER !!!

[@adavidson116116]

Thank you for this. I just caught a manifold leak on my 02. Shed only misfire when idling without really cold outside temps on when the engine was cold. Did this water test after reading a code of lean. And she started misfiring abit and smoke would pickup out the tailpipe.

[@ScannerDanner]

Sweet! It's a great test for sure

[@mikevonkleist6767]

That was brilliant, my friend. That's called being a good tech. God knows, I have to borrow a smoke machine from someone. Thanks for this.

[@ScannerDanner]

thank you mike!

[@aaronmcgee9062]

ScannerDanner your the best I swear u the real deal

[@nicholaselias8542]

my bro-in law's 2008 trailblazer was throwing a p0171 code with similar data. i also suspected vacuum leak and did a smoke test and found smoke billowing from the intake. it turned out some of the bolts had backed out and I tightened them and then the numbers went back to normal. they were so loose i was surprised they didnt fall out

[@Forests444]

You tightened some bolts on your vacuum leak?😂😂😂😂😂 probably not what you did!!

[@Herbotune]

Thanks so much for this excellent information which you present very well. I have a similar car with similar symptoms and codes. Very, very helpful.

[@stephenbates8370]

another exelent presentation. thanx for going through the prosses of elimination that makes all the difference for me :)

[@giovanyrivas9600]

Ur genus thanks to share ur knowledge i hope u millions of happy clients

[@damianward2578]

Nice diagnosis Paul, this is the first time I have seen the smoke tester in use, very impressive. The smoke testers also may be used to locate tricky exhaust leaks in the engine compartment I understand.

[@JMATUS24]

Reminds me of my instructors in school. Your the man!

[@dannychuqui4797]

Good videos as always..... thanks for explaining us.....keep up !! and is good thing when is explained with examples to better understand ing and finding different ways and much easier to work in cars......good job!!

[@joelthomas3823]

Awesome, same codes and symptoms cold, did the water test, engine started running rough , intake leak of drivers side rear, thank you very much for the video!

[@ScannerDanner]

Such an easy and SAFE test. Not sure why some dog it

[@ozzstars_cars]

Good information on intake leaks. Thanks for posting

[@MikeSmith-nu9wt]

I got the po174 not the 171 , i checked for vacuum leaks with carb clean and a straw on the can , cant find nothing , yesterday i drove it around with fuel pressure gauge under the hood ( i need a longer hose ) you ever see a intermediate fuel pump problem ? Gauge quit 6 months ago , its always whined really loud , im guessing fuel pump at this time , 12000 lb atlas hoist broke down , cracked plastic reservoir, and everything breaks instantly , two trucks front tranny pumps went bad on the same day , now this fuel issue ..im running out of trucks , 4 of them flooded outback in the hurricane ( might as well part them out now ) all chevys , 9 of them ..they keep me busy ..it takes 9 to keep 3 or 4 running ..darned old trucks Can i fly you down to florida and get you to help me button up the easy ones ? I'll pay ya well ..i have been fighting them too long .

[@bekomcar554]

Paul, as always deep thanks to your insights, Seoul Korea.

[@chrisbain7773]

I do thank you as I have been to 3 garage's with no help as I have a code P219B as everyone says it is sponsor 2 bank 1 but the light will not come on till I am on the road for 2 hour s . As I do thank you for the water test as that helped me out a lot , I have a 2010 Chevy truck Great Video .

[@efrensaclolo7021]

I did that water test on bank 2 because I could hear a vacuum sucking air sound on my 2004 expedition, Guess what I found out?A loosed spark plug that is about to pop out.I removed and replaced that #6 spark plug with a Dormant repair kit and now it is back to normal.171 and 174 is gone.Thank God.

[@DaveSender66]

thank you Paul I appreciate you sharing this information with us! very much appreciate your willingness to share your god-given talents with the rest of the world I commend you my friend ! Your book is awesome! !!!!!

[@russelldibiase605]

DaveSender66 I

[@operator8014]

That MAF reading is about ⅔ what I would expect to see in a good running 5.3.

[@tam5176]

I've got the exact same codes P0171, P0174 & P0300 broken stud from when I replaced the knock sensors, so will go with the water test in the morning.

[@timowallin8020]

Great one! In here. We hardly have V-type of engines. So mostly only one bank and so it makes it harder to make a call on B1S2O2's if they move like normal o2 on could cat. This one makes a hope that maybe there is ligth in tunnel. To look more then just volt change(at450mv) and make it go on both ends of the range... Thanks for that! That white text on white car is great to read, if you are tired, btw ;) Cheers! Timppa

[@christopherwogen6362]

This vid really helped me i have this Isuzu box truck with the GM 6.0 in it and when I had to smog it, it failed with 180 HC pp so with the bottle of water I found a small vacuum leak from one of the injector seals. I’m hoping this takes care of it. Thanks