BigTom

Hey guys a few weeks ago my check engine light came on and my MPG went from 15-17 regularly to a 12-14 average! I don't know what to do. Any suggestions?? Thanks.

73shark

Go to your favorite auto parts store as most will scan for free to determine what DTCs have been set. That will give you a place to start although it won't necessarily tell you what part to replace.

BigTom

73shark I wen't to O'Rielly's and they hooked it up to a little gizmo and the guy told me that I have to replace the fuel cap and then bring it back and he can reset the codes. Unfortunately, I need to replace it with the same factory cap (so I need to get one from the dealership). Does this seem right to you?

BigTom

After doing some more research and watching this video :
I think it might not be the actual cap itself but maybe just the fuel vent EVAP valve? Any suggestions?

73shark

Did you ensure that the cap was on tight by tightening at least two clicks? If it's not the cap then probably the evap system. Search the forum as there is a lot of info on this and how to replace.

BigTom

So I replaced the gas cap and the check engine light is still on.... Any ideas?

Newto4x4

take it back to autozone or whatever have them clear the code now, and see if it comes back on if it does bring it into a trustful shop

in2pro

I'd make sure the cap is tight and have the error cleared, if it returns then I would pursue replacing the vent valve... DO make sure the sealing ring on the gas cap is clean and that you get several clicks when tightening, also ALWAYS stop filling when the pump shuts off... topping off after pump shut off can force fuel into the vent valve causing the failure...