Silverado Running Rich? I found the problem!! P0172 P0175 4.8 5.3 6.0 6.2

Excess fuel vapor leads to rich codes !!
#keepwrenching #wesselmotorworks #wrenchingwithkenny

[@mikedickman6369]

Just found your channel recently and subscribed. What a wealth of information. Thank you for taking the time to make these videos.

[@markmurdock280]

Man Kenny is a master he knew what size the bolts were for the charcoal canister without having to go through a few sockets he knew the size from previous experience.im always entrigued every video I have learned so much from him

[@dbspecials1200]

Not just experience from removing some, but mechanics can also tell just by looking at the bolt head. I can always spot a 7mm bolt on a an interior component. here are some wrench crosses: 11mm=7/16, 13=1/2, 14=9/16, 16=5/8, 19=3/4 and 21=13/16.. there isn't a good standard box-end match for a 9,10,12,15,17,18mm.

[@byenzer5101]

1. At 02:05, you verified the purge valve was "not" passing vacuum when it is "OFF". That's a good test. 2. Unfortunately, you didn't use your scanner's bi-directional feature to send the computer a command to turn the valve "ON" and thus, verify it works and is indeed operational. 3. Furthermore, the amount of "raw fuel" that dripped out of the evap can was "not" unreasonable. A couple of drops is totally O.K., as this could simply be only a mixture of water vapor condensate mixed with normal fuel vapor condensate. (Remember, the truck was just sitting for many hours, allowing condensates to pool at the bottom of the evap can.) 4. You can manually activate the purge valve, via back T-Pin back probing the valve power connector and simply momentarily touching a test light to the valve's NEG GND pin. (Don't leave it connected to the valve though. Only touch it to command it "ON" and feel for vacuum again. You should also hear and feel a "click".) 5. My guess, there is still a problem with the evap system, and it will only be a matter of time before the problem resurfaces again.

[@Fierofreak01]

Thanks for pointing me in the right direction. I had an intermittent p0175 and P0172 on a recently re-sealed engine, so definitely not a gasket. Although, it wasn't a saturated charcoal cannister it ended up being the purge solenoid would stick open and cause my short term to peg at -30 at idle. After replacing with an actual GM solenoid, short term went to normal. I appreciate you taking the time to posting this video. -Jason

[@BurgerBin]

I was wondering about this as well if that’s my issue seems my trims nearly match each other but I feel like they’re too much where it’s a faulty sensor for the o2

[@marknarveson4853]

A few years ago (about five years) I asked different mechanics about when to change a canister. Not one of them knew anything about canisters. All certified mechanics.

[@mc5216]

Also with the 2014 up Silverados and Sierras with the 5.3 gdi engines, the high pressure fuel pump will cause the rich codes as well. My 2014 had that issue. Replaced the high pressure fuel pump and change the oil. Cleared the codes, and had no issues since.

[@dakotahendrix9037]

I hate that you said this. I hate intake work.

[@vurzr3049]

I have rich fuel. I changed bank sensors and still popped up. Will the high pressure fuel pump be the problem?

[@theadorephaedon1691]

See

[@dejanmilasin6543]

😊

[@salserr5022]

Another great video and tip, I see this all the , I work on police interceptor all day long, I'm changing the canister all the time because they overfill by topping of the tank. Kenny some people just won't listen. Great video. 👍

[@M21-w1y]

Yeah, I used to fill gas to the top too. Not anymore, when the pump clicks off, I pull the nozzle out. It’s no fun changing a canister out on a ‘07 Tahoe!! Why can’t they make all those connections the same?!?!

[@oldbiker9739]

my 2005 s10 blazer wouldn't fill with gas, so I took off both big hoses and took a 5/8'' heater hose and couldn't blow through it , took out the canister cut the top off and pulled out the filters and the charcoal and glued it back together and all is good now ,its just a winter beater.

[@WrenchingWithKenny]

Nice !!!

[@johndee68]

I guess if the evap purge solenoid hose going to air is removed while monitoring the fuel trims, that'll show if there is an issue caused by the canister if the trims go closer to zero as well.

[@anonymuswere]

that explains what was going on with both a Montero Sport and a CRV I had that wouldn't let me lock on fill at the pump. add that to the 'automatically replace in every used car' list. I've learned more from watching you repair guys vids over the last year...

[@ross_ulbright7779]

I was waiting behind a guy at the gas station and he literally spent 5 minutes trying to fill his filler tube to the top. I just sat and wondered how much fuel his purge canister will hold .😂

[@WrenchingWithKenny]

😂😂😂 it is crazy to me! Thanks for watching & keep wrenching 🔧

[@bokidori]

Had a same issue with 2014 Sierra Replaced charcoal canister just like you said The issue and scan codes has gone. Thank you so much

[@WrenchingWithKenny]

Glad I could help. Thanks for watching & keep wrenching 🔧

[@hawk66100]

I’m currently having the same codes. P0172 p0175. I’ve changed the fuel injectors, spark plugs, mass air flow sensor but the codes keep coming back.

[@holeshot1721]

@@hawk66100clean the throttle body and get new 02 sensors from the auto store not from online with all this fake oarts flying around! Autozone warranty them for 1 year

[@jeromyoberpriller1014]

My truck has the same problem, I just got a evap canister from a wrecked truck at my school yesterday and hopefully that fixes it.

[@WrenchingWithKenny]

Hopefully it does !!

[@loganbente6459]

I know in some of the later model year Silverados we see at our dealer if the truck has been under a lean condition for awhile the ECM will interpret it as high alcohol content in the fuel (E85) some models don't use alcohol sensors and the ECM just uses an algorithm to calculate alcohol content. Once the ECM learns the "false higher alcohol content". Any change in temp affecting the lean condition "sealing better" the fuel trims will go rich. I've seen at least 5 cases of this so far.

[@davidmorales4915]

What is the fix for something like that?

[@garrettfrickel]

Is this just fixed with a re flash or reset?

[@brentowen780]

Nice to know what causes this problem, our gas tank clasped before..

[@Rodeo32145]

Some emissions switches are vacuum controlled. So yes a leak in the vacuum supply to a switch will give you problems.

[@donniee1934]

My 2011 Ford 6.2 gas The info screen read tighten gas cap. So I stopped and open cap and tighten it. Next day check engine light came on. I hooked up my cheap scanner and the code was for a small vacuum leak. I checked the cap and it was still tight. So I disconnected the wire for the purge valve and it was sucking vacuum. So I checked local parts stores and no one had one (?) So I removed the purge valve to inspect to see if it had dirt holding it open. Clean as could be. So I attached 12v to it and it would not click so I figured it was stuck in the open position. I whacked it down hard on the workbench and then it would click and open and close like it should. So, I put it back on and have had no more codes. That was 6 weeks ago and it's still fine, no codes. I did purchase another valve so I'll have it should the problem come up again.....

[@Americadoe]

Thanks for mentioning the rich code due to vacuum leak issue. I've been working on a 2001 4.6l ford rich at idle. Fuel system is fine. I guess I'll move to check for vacuum leaks.

[@TheMajictech]

The intake gaskets setting rich codes is the map sensor seeing less vacuum. Probably was only rich around closed throttle.

[@dereksimenac8844]

Certain models with vacuum leaks will set rich code because the 02 sensors are not the only way to set a code. There is also a code setting criteria for when more fuel is added compared to the amount of measured air. Even if O2 readings are good you can still have the code

[@chadbailey189]

thank you for video, it's simple in a way I can understand. I'm having same problem. I'm a gear head, but emissions it's a little tuff for me

[@dbspecials1200]

It might make sense in that the processor is trying to compensate for the vac leak, and in some instances that would be in the form of mixture enrichment, but to an excessive degree (?) 🤔

[@JOKERPanda-l9i]

My 2015 was doing the same thing. Was told it was the o2 sensors. Replaced them and the MAF sensor. Still didn't fix the problem. Come to find out the high pressure fuel pump under the intake was leaking into the crank case causing the truck to run rich. Finally found the problem because there was gas smell in the oil.

[@RamonLFrancisco]

Great video Kenny! I appreciate you sharing your knowledge!

[@terrywilliams6820]

Great video guy.. you do a great job.

[@lawrencecavens5760]

Another great video Ken. You Are a Great credit to the industry - Like - Eric O/ from South main auto, - Brian { from Fordmakeyouloco Channel } BSM Automotive I think his shop is called, - but any how Keep on teaching as you are doing - It's a great way for those of us to get up to speed and learn new things. Thank You!!!

[@robertbragg9364]

I have these codes with several more. I changed coil packs plugs O2sensors a MAF sensor. Im gonna try this next. For $90 its worth a shot. I need an echeck ASAP. Hopefully this will work for me too! Thanks.

[@youhappyf0o]

How’d it go

[@robertbragg9364]

@youhappyf0o didn't fix anything and still don't know what the problem is.

[@youhappyf0o]

@@robertbragg9364 did u try map sensor ? Injectors?

[@robertbragg9364]

@youhappyf0o MAF Sensor was replaced first. I checked voltage/amps on fuel injectors. The guy that did the read said they were all working properly and in the correct parameters. The alcohol percentage is around %35 and should be between -%10 - +%10. It's dumping extra fuel which is causing the black smoke and loss of acceleration on the highway around 45mph. When i tried pulling a small uhaul trailer my truck had no acceleration on hills and the rpms almost red line if you hold your foot on the pedal and try to not lose your speed and momentum. Then you have to let off when the truck revs out of control. I tried using cruise and that was a nightmare and tried foot driving. I just did a 14 hr trip to Florida and it took me 20 hrs because of the hills. I was only hauling about 2300 pounds. I expected it to take and hr longer but losing 6 hrs on a 14 hr trip isn't right. I just need to find someone near Cleveland, Ohio, who knows what they're doing. I definitely don't know anything when it comes to computers or electronics but I can fix any problem if someone knows the issue. I'll even drive 2 or 3 hrs in any direction I'd someone can help me get the problem fixed. I'm also not looking for anything for free. I'll gladly pay the cost. I have $14,500 in my truck, I own it and it has around 150,000 miles and it's a 2011 with a check engine light. It has 4 codes, some repeat and they're permanent and temporary codes. Dont know how much that matters or helps. I have a 2003 with 250,000 it runs perfect with no check engine light. Only an airbag light. I'm usually good at fixing anything gmc or chevy but this truck has me stumped. If it didn't affect the drivability I wouldn't care but this Is the nicest vehicle I've ever owned and it's one of the worst running I've ever had. I gave up on ford years ago because of electrical issues I couldn't figure out and now this is the first chevy I can't figure out the issues. Any help is greatly appreciated. 🙏🏽

[@youhappyf0o]

@@robertbragg9364 there’s a list I found online about what are the most common issues that caused these two codes. But it’s a lot of diagnostics that I probably cannot do and I don’t want to keep wasting and wasting money to end up in the same situation. Idk what else to do,.. someone said it’s the injectors

[@rebdawi2002]

Vacuum lake makes total sense, because not enough O2 will mess with the fuel/air ratio.

[@jdavis8610]

Those charcoal canisters ain’t cheap from what I understand.

[@mattreuther3424]

I have a 2013 Avalanche, and I’m 95% sure I have this issue. I’m getting the same codes and I have the issues with pumping the gas. Wish I saw those before changing the oxygen sensors.

[@nunya8048]

My 99 is throughing rich bank 1 and 2 and LTFT IS -10.9 which means its takeing fuel away. Whats messed up on my end is everything is brand new...injectors and complete rail system, throttle body, map sensor, new complete evap system EVERYTHING! Even the entire intake duct. No vaccum leaks etc. STFT bounces 4 to -3.5 both sides...LTFT stays -10.9 unless rev it up and it comes down slightly.

[@roderickr35]

Check your fuel tank pressure sensor, it will cause all three EVAP ,map, and MAF bad, mine was coming apart, sucking air straight thru

[@goldwingconepatterns2565]

I wonder if correcting the overfill situation would the charcoal canister empty out and save changing the canister. At the risk of sounding cheap with that question it is more that I try to avoid wasting something that could be saved.

[@rickwidlund3512]

Another great video, with knowledge added.

[@ThisIS_Insane]

This was Great!! 👌👌👌

[@chevyman6837]

The reason why a vacuum leak won’t throw a lean code is because is getting on metered air and it will add more fuel to corrected

[@mikem5475]

That doesn't make sense. O2 sensor seeing air = lean

[@imzjustplayin]

@@mikem5475 you only get a lean code if the metered air which is the air that is measured/calculated by the MAF, MAP and Barometric pressure sensors doesn't align with what the oxygen sensors are seeing. Oxygen sensors are really just a feedback loop for fine tuning. If you see a vehicle with large fuel trims +25% -25%, that can only happen because the oxygen sensors aren't agreeing with what the computer is expecting. Ideally the fuel trims should be 0% and that happens when the car's computer is correctly metering the air coming in and injects the appropriate amount of fuel and that fuel is combusted as expected.

[@mikem5475]

@@imzjustplayin good information and what I said still stands, vacuum leaks cause lean codes

[@perryreasch1209]

ANOTHER GREAT VIDEO

[@thomask4836]

My wife and I have a running bet going on about the name of church where you stop during your test drives. I say it's the Divine Brotherhood of the Torque Wrench. My wife says its the Little Sisters of the Sacred Solus.

[@WrenchingWithKenny]

LOL !! I actually think it may be the Church of Speed !!

[@josephmawhinney9280]

Had a truck in the shop today that had this codes as well checked for vacuum leaks checked the purge canister was fine found out the octane level in the gas was to high ran the gas down put lower octane gas in it the codes went away

[@emptech]

If you had the time, could you leave the charcoal canister in a warm area for a while for the gasoline to evaporate and re-use it? With my 2009 Suburban, I normally drive at less than 200 feet above sea level. A while back I was driving into the mountains, over 6000 feet and got an engine check light. The vehicle seemed to run OK, got the error code, rich air/fuel mixture in bank 1 it says. I cleared the code for now, seems to be normal. At 6000 feet should have been a leaner mixture, I suppose if something wasn't working right and the system didn't lean the mixture, it would make sense that it was too rich, right? I'm about to purchase a newer and better code reader, actually a bidirectional one so I can check the solenoids. Should I ignore the codes since they have not come back? I like your down to earth video, you say it like it is. Jim

[@boringoldman]

Why do they make such pain in the butt connectors 🤦🏻‍♂️

[@ericflores5748]

So I have a 2016 Tahoe and started with a P0172 and P0175 can't find the problem and now I'm getting also a P0430. I'm going to follow your instructions and see what happens.

[@huttoerik28]

What happened?

[@Mustangg16]

Wow 2014 and no rust on it

[@huttoerik28]

So you're telling me it was not the high pressure fuel pump leading fuel into the engine oil?

[@evanhb49]

i unplugged where you checked for a vacuum leak and my was just suckn away. that means i can rule out that 180$ charcoal box?

[@manuelcarrillo7607]

Why does the gas tank have all those wet drips all on it and what caused those drips around the tank?

[@kevinu2993]

Won't evaporate/dry back out after a bit as long as You're not topping off anymore.?

[@ledbetterjack]

If the carbon pellets haven't disolved into powder

[@florenbaron7111]

Should this problem cause drivability issues like reduced power, delayed acceleration, low gas mileage, etc?

[@hotrod8915]

No. He is inventing a problem and pretending to solve it. He is not even checking vacuum to charcoal canister correctly.

[@robertjeffery6100]

I tell people all the time at the pump why they shouldn’t be overfilling there tank they look at me like I’m from outer space

[@WrenchingWithKenny]

I do the same thing & get the same reaction! Thanks for watching & keep wrenching 🔧

[@1Turnatatime]

Do you just start the truck after replacing it or do you let it idle before driving, i didnt want to screw anything up just after replacing it

[@ericflores5748]

Why I get p0172 p0175 only when I'm parked car on for 15 or 20 min

[@thrillbillyjp1]

Ur checking the wrong end of vacs. Checking above on top manifold in closed will show u pull.

[@garrydonohoe7169]

Could the computer be over compensating for a lean condition

[@BRED23]

Any idea what could be wrong with my 99 5.3 1500 it runs good only on cold start the rpms will drop and it will die once it’s warmed up it runs like normal again

[@AZHerps]

Would a saturated canister cause a real rough idle?

[@jliscano5]

I have a 2010 silverado with a 6.0 engine swap power on 65 psi fuel running drops to 40 psi

[@WrenchingWithKenny]

Is it direct injected EFT? Or old school EFI?

[@marksmith7896]

Like !!!!!!

[@sandravela2760]

where did you get the canister

[@esperformance2308]

Would this also cause the computer to calculate a higher mpg?

[@jeffreysmall5259]

Me too.

[@stephenrickstrew7237]

Tales From…. The Go Figure Zone …

[@rickycrowe7702]

If your sucking air in the seal down below the m.a.s. And it reads more air at the 02 sensor it will dump More fuel to compensate.

[@Fran-yg4jp]

Could this happen on a 2013 Chevy avalanche ? 5.3

[@elgordosabroso72]

Where are you located in North Carolina

[@WrenchingWithKenny]

Currently in Shallotte.

[@martintopete9188]

Hey good info here, but does this also go with the 07 classic Silverado? I’m having those codes come on but im thinking it’s the charcoal canister , having issues filling up the tank when pumping gas and smells alot when truck is on

[@1Turnatatime]

I have a 2012 sierra, I just replaced my canister, I thought it was the filler neck since it was rusted, I haven't driven yet but I had similar symptoms. My mpg was terrible, I had almost 3/4 of a tank and by the time I got home it was down to a quarter and my drive was only 35 miles. I would smell fuel stepping out the truck and sometimes walking up to the truck. The canister did kind of smell like fuel and the lines. Change it out and see. I remember the past few times before I would fill up and top off thinking I was getting more gas but it seemed to backfire on me lol good luck

[@oldbiker9739]

people stop pulling the trigger when filling up its not a gun its a nozzle, lol

[@WrenchingWithKenny]

You are absolutely right !!

[@maxmohr7860]

What about a p0701 running rich in bank 1

[@agger838]

That u shape clip u just press on to disconnect

[@shinigami117s8]

So wouldn’t it eventually suck all the fuel out of the canister?

[@kellismith4329]

Actually the charcoal will break down and will be drawn into the lines

[@williepotts2185]

Dust is the problem.

[@bwagenberg]

Why WD instead if silicone spray?

[@ross_ulbright7779]

WD smells better. It's like cologne for your car.😂

[@carlosvteck]

❤❤❤❤p

[@nunya8048]

Those -8 and -5 are bad numbers. They should be close to zero as possible. STFT should bounce between +3 to -3 or constant to zero as possible. Your problem is still there

[@michaelmessano3033]

My corvette will run rich as pig (Ls3) when NPP IS OPEN on exhaust valves. That is the ECM COMPENSATING for lean code

[@hotrod8915]

Naw. Do a compression test on each cylinder.

[@fredyounger5850]

WELL IT SUCKS THE RAW GAS FUMES FROM THE TANK INTO TO ENGINE AND THATS WARE IT GETS THESE RITH SMELLS FROM TOO

[@johndee68]

I guess if the evap purge solenoid hose going to air is removed while monitoring the fuel trims, that'll show if there is an issue caused by the canister if the trims go closer to zero as well.