Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture Mobiletron "OS-B4160P" - Not availableBMW - 3 (E46, WB), 7, X5, 5, Z3; AUDI - A6, A4; CITROËN - Berlingo, C3