Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture MDR "EPS-1997 963" - Not availableBMW - 5 (E39, WB), 7 (E65, WB), 6, 3; AUDI - A6, A4; ROLLS-ROYCE - Phantom