Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture RIDEX "3922L0539" - Not availableBMW - 3 (E36, WB), 5, 8, Z3, 7; MERCEDES-BENZ - Vito; ALFA ROMEO - 164, 145