Before changing any gas caps. Why don't you try using a fuel injector cleaner. Get a real big / or the bigger fuel injector cleaner you can buy and pour it in on your next fill up. I bet after the next fill up or two everything will be ok. I had the same problem on mines. The only way to check, if your cap is bad go to a local state inspection shop and they will check it for you for a small feed of course.
AutoZone will check your computer codes for FREE.
The check engine light comes on when the main computer senses an error in something electronic such as a bad sensor or wire. The easiest way to see what it is is to go to autozone or a dealership or someone with a scan tool and have them read the codes from the vehicle. Autozone does it for free but a dealership will charge for it.
Well, at my corner AutoZone, it's $7.09 + tax. Check at WalMart, AutoZone, Advance, Murray's, whatever...
take it to the autozone they check the engine light for free
get a trouble code tester, autozone will check your car for free
With scan tool, go to Autozone and they will do it for free.
On a 2002 Ford Expedition : The " check engine " light is the " SERVICE ENGINE SOON " light just to the left of the fuel gauge
if your take it to a autozone tell them you have a check engine light and they will tell you whats wrong if anything and reset it take it to autozone and tell them your check engine light is on and they should reset it
take it to autozone and have it scanned
Have AutoZone check for codes (FREE). It may be a bad coil pack...
and what code does the check engine light say ? go by autozone they will check it for free and get the code.
Go to "Autozone" and get them to do a readout.Find you an "Honest Mechanic" and get them to fix it,ok?