Fuel cap/CEL

[Chimpy]

I have already read some posts on this topic but my EVAP codes go back and forth between a small leak and a gross leak with a CEL thrown in randomly:no:
Tried the obvious fuel cap replacement and it was good for a while then came back. There has never been a problem with the Hummer not taking gas when I fill it up. I have never over-filled the tank since I have owned it. It is aggravating because it happens so randomly. Any tips?

 

[mjferencak]

I've had that code for four years now and I keep telling myself I'm going to fix it. I've been told that it's my EVAP valve/canister/solenoid but until I change it I really don't know.

 

[Chimpy]

I have read about the solenoid. I replaced what Toyota calls the purge control valve on my 2001 4runner. It wasn't too bad of a job. Sold the 4runner, now have a Hummer with what looks to be the same issue. I need to get my hands on a GM Tech II.

 

[Kinson33]

I have already read some posts on this topic but my EVAP codes go back and forth between a small leak and a gross leak with a CEL thrown in randomly:no:
Tried the obvious fuel cap replacement and it was good for a while then came back. There has never been a problem with the Hummer not taking gas when I fill it up. I have never over-filled the tank since I have owned it. It is aggravating because it happens so randomly. Any tips?

Do you have the 5 or v8? Does it ever hesitate after filling up?

i changed out the purge valve on our 5.3 suburban and it took me fifteen minutes, problem solved.

 

[Chimpy]

I have the 5 cylinder. I have read some other threads that have me questioning the battery terminals. About 2 months ago, I went out to start my H3 and the battery was dead. I got a jump from a friend and drove straight to my buddy's shop and had a new Interstate battery installed. Within a few days of the battery change, the fuel cap light suddenly came on then the CEL. After that, the ABS and stability lights both came on. In the last couple days, the ABS light will go out but the stability light stays on. The fuel cap and CEL had been coming on separately and the codes were either small leak with just the fuel cap warning or gross leak with both the fuel cap warning and CEL.. Since using my code reader to erase the EVAP codes a week ago, they have not came back on since. Battery terminals aren't expensive and from what I have read, a necessary upgrade. I will see what happens.

 

[Kinson33]

Low voltage can make a lot of things go goofy. Terminals are a good start.