Quote:
Originally Posted by familytruckster  Leave the battery disconnected for longer.
Where in PA are you, I am in Hanover and have a scan tool.(and can clear it for you) |
Codes are stored in the ECU indefinitely until they are cleared with a scantool. Even if the CEL goes out on it's own which is common if the problem is fixed, such as an o2 sensor being replaced, a misfire, a vacuum leak or an evap leak(gas cap left off or bad seal), the codes will still remain stored in the ECU even if the light goes out on it's own. Simply disconnecting the battery isn't going to clear anything except maybe your security code if you have a stock radio.
To clear the codes, first you need to ensure the problem is fixed(read the codes first and make sure it's what you think it is), hook a scantool up and clear the codes. Most reputable shops will check/clear the codes for free, as mentioned by b.u.ti-ful, some autozones will loan you a scantool or check/clear the codes for you or you can pick up a cheap scantool at harbor freight, your local auto parts store or on ebay. If your car is a '95, you'll need an OBDI scantool and if it's '96 or newer, you'll need an OBDII scantool.