The check engine light on my 1997 Honda Accord has come on twice while on long trips. The first time the dealer said it was a "false code" and reset it. Now it's on again. Can I reset this myself? It has 28K miles.
You can clear the diagnostic trouble codes from the PCM (Powertrain Control Module) memory all by yourself, but it's not going to fix anything. I'm not quite sure what they meant by "false code", but if the check engine light did come on while the engine was running; there is a problem -- period. If it showed a code that doesn't exist that would be a strong indication of a fault within the PCM itself.
To clear the codes simply go to the fuse panel under the hood and remove the Back Up (Radio) 7.5amp fuse for ten seconds with the ignition off. Then the next time the check engine light comes on bring it back to the service department and tell them your problem is for real.