Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture Metzger "0893568" - Not availableAUDI - A8, A6, A7, S6, A4; BMW - 3, 5; FORD - Focus, Fiesta; HYUNDAI - I30, Elantra