my 2005 Colorado had a check engine light on with a gas cap I replaced gas cap light went off it may be someone took mine and put their bad one on ? oh the year above only went to 2002 guess they didn't think a truck that's only a 2005 should have a BAD cap on it the truck was a year old when I replaced the cap seems Government motors needs to use better products
I had the vehicle in for yearly State inspection. Check engine light had been coming on after ignition and then going out after a minimum of 1/2 of driving. In order to pass inspection cause and repair had to be identified. $1100.00 later new gas cap solved the problem.