2004 Envoy check engine light

[jjrbradley]

I just bought this Envoy Tuesday afternoon. Have driven about 60 miles so far. Check engine light just came on this afternoon. Running absolutely fine. The fuse blew on the cigarette lighter, but that is all. Any ideas before I get it to the service people to have it checked?

 

[Bassbone]

I've found my gas cap has been the culprit. My Envoy would throw random codes. I re-seat the gas cap and the check engine light goes out.

 

[jjrbradley]

Thanks, I found out it was a bad thermostat.