Started the car today and it idled fine for a few minutes. Then the air fuel went rich and the engine threw a code (Both upstream O2 sensors stuck open rich). What would cause it to do this? Would just replacing the O2 sensors fix it or will it happen again from some other cause? Car has 12,xxx miles, would an O2 sensor just go bad all of a sudden or is something making it go bad? Any help I would greatly appreciate it, Thanks.
