Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture VEGAZ "ULS-253" - Not availableBMW - 3 (E30, E36, EC), 8, 5, 7, Z1; ALFA ROMEO - 155, 164; CITROËN - XM, Xantia