Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture Delphi "ES11108-12B1" - Not availableBMW - 3, 5, 1, 6, 7; AUDI - A4, A3; DAEWOO - Matiz; ALFA ROMEO - 159, 156