Gas cap CEL

About a year ago, I had a CEL and the dealer said the gas cap wasn't properly tightened. They tightened it and cleared the CEL. Last week I saw a CEL and removed/re-installed my gas cap. The CEL cleared on its own. Now, I got a CEL this morning... I'm guessing the cause is the same.

 

I guess I need to get a code reader, but say the code reader gives me the code for a gas cap. I can replace the gas cap o-ring (it looks fine), but is there anything else that can cause the gas cap CEL besides the gas cap? Is there some pressure valve or a charcoal canister that could cause this CEL? It's quite annoying and I think I do, in fact, know how to screw on a gas cap...

There are about 70-100 reasons why the CEL can come on and I am using a relative small number of reasons.

process of elimination... get a new gas cap and see how it goes.

 

if it still fails, get a new car.

I had the same thing last month, just had autozone scan it to find the problem, although the codes on their system are different than the thread here that lists what the codes actually are. If you tighten everything up and want to manually reset it, just take off the negative battery terminal for a couple of minutes, and pump your brakes a couple of times when you do so.

>>but is there anything else that can cause the gas cap CEL besides the gas cap? It isn't exactly a 'gas cap CEL'. It is basically an emissions code indicating that during the fuel system integrity test, the ECU believes it detected a leak. That could be the gas cap, or it could be somewhere else.