Who in the LA area would be a good choice to see what activated my check engine light?
Modern Auto Techonology in Pasadena. Why don't you drive it a while and see if it goes off, first. It likely will. Check engine lights are more about EPA/emissions stuff than anything real screwy happening with your car. Your REAL check engine lights are water and oil temps. Of course, you can always check the fault codes yourself from your ECU quite easily.
