Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture NTY "ESL-MZ-011" - Not availableBMW - 3, 5, 1, 6, 4; AUDI - A4, A3; MAZDA - 2, 3 (BK, BL); ALFA ROMEO - 159, 156