My 1997 Tercel has the check engine light on. The mechanic says that the codes it's throwing are random misfire or piston 1 misfire. We have replaced all spark plugs, wires, both coil packs, and the cam shaft sensor and the car is still misfiring it seems ONLY when idling and runs smooth once driving. I have no idea what to do at this point and i'm out of money. Spent about 600 on this already and smog and registration is due in a week. Any idea what is wrong here? I've seen the check engine flash for a few seconds twice in the past couple months. I hear that a flashing light is really bad