Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture INTERMOTOR "64421" - Not availableBMW - 3 (E30, E36, EC), 5, 7, 8; PEUGEOT - 306, 405; CITROËN - ZX, Xantia