Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture Kawe "8845 50021" - Not availableBMW - 3, 5, 6, 1, 7; AUDI - A4, A6; MAZDA - 323, Premacy; ALFA ROMEO - 159, 156