Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture Gebe "9 7124 1" - Not availableBMW - 3, 5, 1, 6, 7; MINI - Cooper, Clubman; CITROËN - DS3, C4; PEUGEOT - 308, 207