My little writings on brake repair
Whatever you do, do not take your car to an auto parts store when the check engine light goes on. Auto parts employees are qualified only to interpret the trouble codes, not to diagnose and repair. Go to a certified technician if you want service done right. Minor issues like a loose gas cap, bad spark plug wires or moisture in the engine can trigger a check engine light. If your light indicates a non emergency, first check your gas cap and then your engine for wetness before taking your car in for repairs.