2008 Cobalt Ls Xfe Fuel Efficiency Problem/ Check Engine
So, New to the forums :o i just bought myself a nice little 2008 cobalt only 102k miles on it for a steal nothing wrong with it but since i got it from the lot there has been a check engine light. i took it to advanced and autozone and they both said its a fuel efficiency code and to just use higher octane gas and c-foam. when i asked the specific code they didn't tell me so im at a loss... i'm about to go on a road trip tomorrow (dolly wood) and it has been EATING gasoline like crazy, i have been using 87 octane and only drove a little bit and it keeps going empty :/ any help would be great! When i was looking over his shoulder it said something like cata efficiency?