Lots of confusion with my EVAP CEL code

[davidsSLT]

So im throwing a CEL and it is P0455, im sure you guys have read about this on here or experienced it yourselves. But I did some research on here and on google on this code. I have an 03 Yukon SLT with flex fuel

Its the large leak code. I replaced my purge valve solenoid on the intake manifold since it was the cheapest fix. Still throwing the code.

Got under the Yukon and see moisture all over my EVAP canister, I suspect this is where my leak is.

However, all the research I am finding is that the problem is with the EVAP controle valve solenoid on the back of the tank above the rear end.

Looking back there, and comparing it to the picture in my Chilton manual they look the same. But when I try to find the part online I get a total different picture, lik e part number VCS301 on autozone.com.

Im wondering, should I replace my canister because it LOOKS to be the problem because of the vapor/moisture? Or is it the EVAP vent valve control solenoid? Chiltons manual says P0455 is EVAP system is unable to reach calibrated vacuum level.

Sorry so long, I wanted to be specific.

Thanks.

 

[BRUTUS_T_HOG]

The vent valve is a very high fail item. GM has a TSB and updated part kit for it, that is eh it looks different. I would bet on a sticky vent valve before a canister. You can take the lines off the canister and check for liquid fuel or water if you find liquid replace

 

[davidsSLT]

The vent valve is a very high fail item. GM has a TSB and updated part kit for it, that is eh it looks different. I would bet on a sticky vent valve before a canister. You can take the lines off the canister and check for liquid fuel or water if you find liquid replace

Thanks man, ill start with the vent valve. I have seen that part your talking about that looks different, I never knew GM had a different part for the fix. Thanks again.

 

[davidsSLT]

Brutus you were right, it was a sticky vent valve.

The service guy explained to me that my vent valve isn't a spherical one like the normal ones you see, (thats why I was having trouble finding it by my tank). Mine is a square shaped valve, maybe because of the flex fuel?? who knows. Anyway the charge was 191.00. Took a whole hour at the most to get me done.

Thanks again!