Silverado 1500

Check Engine Light Due to Gas Cap Issue on Chevrolet Silverado 1500

Problem Description and Possible Solution

A Loose or worn gas cap may cause Check Engine Light to illuminate.

Problem Data
RepairPal Verified
Average mileage: 90,776 (44,550–208,700)
4 model years affected: 2006, 2008, 2009, 2010
28 people reported this problem
Viewing 1 - 7 of 7 comments
i replaced the gas cap and had the computer reset....3 days later the truck told me to tighten the gas cap again. now the check engine light is back on.
Diagnostic code comes up to say emissions leak and was told preferably to change gas cap, but when I did replace the cap, I unhooked the battery thinking it would reset and if the problem had been resolved then the check engine light would not come back on. Not the case, however, because the light came back on and I am again looking for a resolution.
Engine light comes on- attributed to a sensor for emission control
Replaced it but it returned less than a week later
Check Gas Cap came on the DIC once. Checked, it was tight. Message did not reappear. About 2 weeks later, the check engine light came on. I said it was the fuel/evap system. Replaced the gas cap, but it did not fix the issue. Now looking for other problems. Found the undercoating above the left catalytic converter, below the master cylinder looked wet and is sticky. The fuel lines run through this area. Suspecting leaking steel line, but could not find it with engine running. There is no smell, so I suspicion the fuel is evaporating and just softening the tar.
180 3000 problem that I'm having is the tighten the gas cap keep coming on I put a new a canister and I put a new pressure – pressure sensor on and I still having the same problem