Engine code

Too rich bank 1. A dirty mass air flow sensor overstating the amount of air entering the engine which may cause excessive fuel delivery. A bad oxygen sensor. A leaking fuel injector allowing too much fuel to enter the combustion chamber. A faulty fuel regulator, which may not be regulating the pressure of the going to the engine as it should. A vacuum leak. A possible fault in the coolant system such as a stuck thermostat or bad coolant temperature sensor.