Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture HC-Cargo "181822" - Not availableBMW - 3 (E46, WB), X3, Z4, 5, 1; AUDI - A4, A3; MERCEDES-BENZ - C-Class, E-Class