Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture FREY "880601901" - Not availableBMW - 3, 5, 1 (E81, E87), 6, 7 (E65, E66, E67), X6, X1, X5, X3, Z4