Well, I have a quick question...hopefully. I just noticed my gas cap light turned on yesterday and doesn't want to turn off. The cap is tight, and I don't have a CEL either. Is the cap just not sealing?
It probably just means that the cap isn't sealing, or it could have something to do with the evaporative emission control system that filters most of the vapor out of the air that comes out when you refill the tank. If you're still in warranty, I'd take it to the dealer, otherwise start with the cheapest solution (gas cap) and work your way up from there.
Like BornAgainFordOwner said it will take multiple trips to clear the light if the gas cap was truly loose after filling. The requirments for the evaporative emmisions drive cycle check is very precise and will only actuallly complete the test every once in awhile.
The light didn't turn on after I filled up the car. Actually, it turned on about five days after I put gas in it. I parked my car at night, and when I drove it the next day, the light was on. I'm gong to try disconnecting the battery for a while and see if the light will shut off (and hope it won't turn back on). I just don't want to have to reset all of my settings for my stereo.
My gas cap light didn't turn on right away either, but that was clearly the problem. Don't disconnect the battery. Clearing the computer is overrated. It just has to relearn all of the fuel mixture trims all over again from scratch.
You may also want to try rubbing some light grease or sil-glyde(brake lube)on the o-ring on yor gas cap every once in a while to keep the seal good. And I have seen some cars that take a month of so before the car will run the evap emissions monitor to turn on and off the light,Depending on driving style.
Its most likly a evaporative emission problem, Like a leaking vapor hose going back to the gas tank or possibly a bad canister vent valve or vapor management valve. It would be hard to find out what exactly is causing this without retrieving a DTC letting you know what the problem is. And if it is a leak, you would need a smoke machine to locate the leak.
Being that it is an emission problem, you might be able to get it fixed under warranty. I hope this helps