Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture VEGAZ "ULS-368" - Not availableCITROËN - C3, C2, Nemo, Berlingo, Xsara; PEUGEOT - 206, 207; FIAT - Qubo, Fiorino