Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture NTK "1948" - Not availableVOLVO - S40, V40, S70, 850, V70; OPEL - Vectra, Astra; BMW - 3, 5; VAUXHALL - Astra, Vectra