Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture BAPMIC "BACB12-741064" - Not availableBMW - 5 (E39, WB), X5, 7 (E65, WB), 6, 3; AUDI - A4, A3; BENTLEY - Continental