Yeah, mine does that too. There's probably nothing really wrong with your car. Those check engine lights are just hypersensitive since the OBD-II computers. As the car ages, it is almost impossible to keep emissions perfectly within spec, and the parameters in the computer are so narrow. I open up the fuse box under the hood and remove the two fuses that are marked PCM. Leave them out for a minute or so and put them back in. This clears the computer without messing up the clock, radio, etc. It requires no tools, it's fast, and I don't even get my hands dirty. After I do this, I don't see the check engine light again for thousands of miles. Hopefully, this will buy you enough time to get it past the smog police, especially since your car isn't a gross polluter anyway.