2005 gmc sierra. Check engine light on for a day or two then goes away for a couple of weeks. Then it will repeat itself. Always before(other vehicles) light would stay on untill i fixed the problem or ignored it. Lolboo -Bob , Columbus
I know I say this a lot BUT "Scan her"
In most cases it something small but make sure its a good scan tool !!!
Not a parts store scan tool.