Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture Delphi "ES21145-12B1" - Not availableFIAT - Doblo, Fiorino, 500, Linea, Qubo; AUDI - A3; LANCIA - Ypsilon, Musa