Check Engine Light Due to Gas Cap Issue on GMC Canyon

Problem Description and Possible Solution

Illumination of the Check Engine Light can be caused by a loose or worn gas cap.

Problem Data
RepairPal Verified
Average mileage: 88,058 (28,000–160,000)
8 model years affected: 2004, 2005, 2006, 2007, more2008, 2009, 2010, 2016
38 people reported this problem
Viewing 1 - 11 of 11 comments
Check engine light...

..turned off after replacing gas cap..
... came on again.. months later.. not fixed with another gas cap..
Check engine light is on again.. Going to have diagnosis done.. but Terrified of being 'sucked into' the nightmare
of "single woman.. unknown problem" .. gotcha.. with Mechanics..!!!

Mass air flow sensor? OMG.. not the catalytic converter!!
My engine light comes on and my engine idles rough, but as soon as the light goes off (randomly) the engine runs fine. The gas cap light comes on my dashboard warning me the it is not secured, I twist of the cap and put it back on, sometimes this will trigger the warning to go off and everthing is fine. That would be wonderful it that was all it was. I am replacing my plugs, air filter and fuel filter to see if these contribute to the light being on.