Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture Delphi "ES11110-12B1" - Not availableBMW - 3 (E46, WB), X5, 5, 7, Z3; AUDI - A6, A4; ALPINA - B7, Roadster V8