My check engine light came on my 2003 H2. Advanced auto told me it was a "loose gas cap" code. I replaced the gas cap but still had the check engine light.

I came across a lot of threads where people replaced their fuel evap canister and/or solenoid. Then I came across this easy fix and it worked.

http://www.hummerknowledgebase.com/f...t_solenoid.pdf

Also this cured the slow re-fueling/gas pump cutting out issue I had. It fuels up quick now.

 

Great post. Thanks.

 

that there is a link that should be pinned