I had the "check engine" and "engine electronics" panel light come on my car while driving yesterday. My car has 108K miles on it...anyone have any idea what the problem(s) might be? Fuel system? O2 sensor? I'd like to have SOME kind of idea of what the problem may be BEFORE taking my car to the dealer. Are there any checks/inspections/tests I can do myself? My car is a '98 E430. Help!