Code P0040 Possible Causes
Bank 1 Sensor 1 / Bank 2 Sensor 1 circuit connectors wrong connection
Bank 1 Sensor 1 / Bank 2 Sensor 1 harness is open or shorted
Faulty Engine Control Module ECM
Faulty Engine Control Module ECM
Faulty Heated Oxygen Sensor H2OS Bank 1 Sensor 3