Thanks for getting back to us on this drvette. This kind of information is always useful for folks struggling with the same issue.*** Just a note that might come in handy ***
As you can see from posts in this thread I also had problems with an engine check light and could never pull a code. I went to a local auto store and bought a new gas cap as this thread suggested and still had the same issue. Finally ended up going to the dealer and they checked for a code. Said it was an EVAP issue and suggested I change the gas cap. Explained that I had already. Said they would clear the code and if the problem came back they would look into further. I explained I had already done that and problem came back. The Tech said only other suggestion is to purchase an OEM gas cap from the parts dept to see if that might help. I purchased an OEM gas cap and my problems were solved. The OEM gas cap solved the problem. Maybe this might help some of you down the road.