The dealer reset my CEL after it came on, but with no problems indicated. It's been on for a week again, no engine anomolies, but my wife wants it reset - do I have to take it back to the dealer again ???

The CEL light goes on when we drive thru an area with woods burning, that's the only clue...

No problems indicated? If the light comes on, there's something wrong. Find out what code(s) are stored and post the results. The CE light alerts the driver to EMISSION control malfunctions. There are several reasons for Check Engine lights that have nothing to do with the engine! I know this sounds crazy, but that's the way it is.

I understand that, but the source of the problem is transient, and not engine critical. I actually think a sensor is "smelling" the burning woods, and reacting to it from a change in the incoming air, like more CO2, less O2, something in the air resulting in improper fuel mixture, etc - I just want to know if anyone knows how to reset the CEL.