I've searched for this but haven't found anything. I know this can't be an isolated incident. This was happening on my last H2 and is happening on this one now. I have a strong smell of gas fumes from my drivers side obviously coming from around my EVAP canister and/or vent solenoid. It's so bad that I get headaches when I sit in the same spot with the truck running. I'm sure I could pinpoint the problem better if I had a code. Anyone else have this happen? Just wondering if I got mud in something, how I can fix it, and why I don't throw a code. '03 H2 Adventure.

 

I have this happening on mine as well. I haven't tried to track it down yet. I did put a complaint in at safecar.gov about it. Should be something GM has to fix since it seems like a safety issue.

 

evap leak problems happen all the time and not only on hummers . all cars have it and can be in several areas. there is a green cap on a vacuum line under the hood and can be used to pump air into it to listen for a leak with a hand pump . it dont hold a lot of psi about 7-10 psi. this system is complex and most times it sets a code if a part fails but if a line is open it will just say evap large leak. . small leaks are in most cases a bad cap. will look for the exact text to check for the leak in the am . some cars must be running and have over a 1/4 tank and strange things like that. most real scan tools cant test the solenoids . we use a smoke machine to find the leaks .

 

for now follow the vent line coming from the fuel tank and follow it up to the engine compartment just to see it you have anything unplugged or split open.