Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture COGEFA "716.28KY" - Not availablePEUGEOT - Partner, 206, 307, 306, 406; CITROËN - C5, Xsara; FIAT - Ducato, Ulysse