Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture Metzger "0893017" - Not availableCITROËN - C5, C4, Xsara, Berlingo, Saxo; PEUGEOT - 307, 407; CHERY - A3, Tiggo