Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture LUCAS "LEB5459" - Not availablePEUGEOT - 308, 208, 2008, 301, 108; CITROËN - C3, DS3; DS - DS 3, DS 4; TOYOTA - Aygo