2007 chevy tahoe LTZ check engine

[FINALTOUCHFRI]

I had my check engine light come on a month ago. I had the code read and it was suppose to have been the gas cap. I replaced the gas cap and everything was fine until this weekend. Code came on again. I just relealized something recently. When I fill up my gas tank. When I go to start it, it just cranks like im not getting any case. After about 4 tries it starts up and don't have a problem after that. Check engine light is still on!

 

[R3cord303]

I had my check engine light come on a month ago. I had the code read and it was suppose to have been the gas cap. I replaced the gas cap and everything was fine until this weekend. Code came on again. I just relealized something recently. When I fill up my gas tank. When I go to start it, it just cranks like im not getting any case. After about 4 tries it starts up and don't have a problem after that. Check engine light is still on!

Are you sure its for the gas cap and not the vapor solenoid valve thing that there was a TSB about?

I know my grandpa's Ram had a similar issue where the valve was stuck open and after filling up instead of vapors coming out the other end of the line- liquid gas would come out and it would stall the engine.

 

[FINALTOUCHFRI]

They indicated gas cap. It worked for awhile but came back to same problem

 

[iamdub]

They indicated gas cap. It worked for awhile but came back to same problem

Who's "they"? Sounds like the reply of an Autozone "mechanic". Any time they see a code referencing the EVAP system, they immediately suggest a gas cap cuz it's a quick and easy ~$10 sale. Any time an O2 sensor code pops up, they're pushing sensors on you.

I don't see why your '07 would be any different, but mine tells me to "Tighten Gas Cap" when it detects an issue (leak in EVAP system) rather than immediately throwing a code. When you fill up, do you top off the tank?

 

[Doubeleive]

tighten cap message is a "small vacuum leak" most likely next culprit if you already replaced the gas cap is the evap solenoid on the intake under the hood, runs about $25-35 and can be changed in a couple minutes easily. without paying for or doing a evap test you can shotgun the whole thing yourself for about $200 by replacing the evap canister and the two evap solenoids. unless you get unlucky and have a cracked line somewhere but that's not usually the case. Dealer will charge about $100 to run the diagnostic then likely recommend one or more of the parts listed above at there price plus labor which can quickly add up to a total of way more than $200. just my .02

**if you decide to just shotgun it and when replacing the evap canister see little black pellets fall out then just disconnect the plastic lines and blow some air thru it to get them out. those pellets are supposed to stay inside the canister but sometimes the canisters deteriorate and they come out and clog up the lines.

 

[FINALTOUCHFRI]

Who's "they"? Sounds like the reply of an Autozone "mechanic". Any time they see a code referencing the EVAP system, they immediately suggest a gas cap cuz it's a quick and easy ~$10 sale. Any time an O2 sensor code pops up, they're pushing sensors on you.

I don't see why your '07 would be any different, but mine tells me to "Tighten Gas Cap" when it detects an issue (leak in EVAP system) rather than immediately throwing a code. When you fill up, do you top off the tank?

I fill it up but don't top it off.

 

[HiHoeSilver]

Pull the code. It can possibly help narrow this down. Could be po449, po446, etc. If the code points to the vent valve or purge solenoid, they are quick and easy as @Doubeleive said. Canister would be next in the suspect lineup.

The other thing to check would be a leaking fuel line off the top of the pump. This could cause an evap leak, and I say it because of the "takes 4 times to start it" comment. Do you live in the rust belt?

 

[Big Mama]

I just dealt with an evap issue p0455 0452 I think. It’s s general code For evap. I have a decent scan tool but not a tech2. I went cheapest first. Gas cap then no cel for a bit then evap solenoid top of engine no light for a bit finally got my lazy butt under the truck to find the vent line from tank to canister completely off tank outlet and cracked at canister. Duh no wonder the light came back on. Forgot to mention I cleared the code with each attempt but it came back after several days.

 

[FINALTOUCHFRI]

p0449 EVAP VENT VALVE MALFUNCTION. Advance Auto has the valve for $27. Its above where the spare tire is mounted. 10min fix. Will let you guys know Tues! Thanks!!!!

 

[Big Mama]

10 minutes? You da man!! Takes an old fat guy like me that long to open the box it came in.

 

[iamdub]

10 minutes? You da man!! Takes an old fat guy like me that long to open the box it came in.

People like you are one of the reason's for Amazon's "frustration-free packaging".

 

[Big Mama]

Ha you’re right. I got mine from Amazon and the box was so beat up they re-taped it to death. Thankfully us old guys still carry pocket knives.

 

[FINALTOUCHFRI]

That was the problem. Thank you fellas for the input!!!

 

[dross99_si]

That was the problem. Thank you fellas for the input!!!

Which part fixed the problem?

 

[FINALTOUCHFRI]

ACDelco 214-2341 GM Original Equipment Vapor Canister Vent Valve, it took longer to take the spare down then it did to replace the valve. Super quick. Disconnected battery after the repair and code cleared. Yepa!!!

 

[Big Mama]

Thanks for posting the results so the next guy will know

 

[Doubeleive]

ACDelco 214-2341 GM Original Equipment Vapor Canister Vent Valve, it took longer to take the spare down then it did to replace the valve. Super quick. Disconnected battery after the repair and code cleared. Yepa!!!

make sure you give it a couple days to "self check", the code could come back in a day or two if that wasn't for the sure the problem, when it is colder in the morning and you first start the truck and drive it a mile or or two is when the code could resurface, what I am saying is since you cleared the code it may not detect a vacuum leak again until it does the vacuum process again, engine temp has to be below a certain threshold @swathdiver I think has it noted because he had a small vacuum leak also. keep your fingers crossed, I would say if the code does not come back by the 3rd day then your good to go.

 

[swathdiver]

make sure you give it a couple days to "self check", the code could come back in a day or two if that wasn't for the sure the problem, when it is colder in the morning and you first start the truck and drive it a mile or or two is when the code could resurface, what I am saying is since you cleared the code it may not detect a vacuum leak again until it does the vacuum process again, engine temp has to be below a certain threshold @swathdiver I think has it noted because he had a small vacuum leak also. keep your fingers crossed, I would say if the code does not come back by the 3rd day then your good to go.

Yep, P0442, no leak between vent and purge, comes on after 16th or 18th ignition cycle, usually overnight after running those tests. Gotta buy a smoke machine, eventually, other things are taking priority to this annoyance.