Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture RIDEX "3922L0743" - Not availableFERRARI - 5 Maranello, F355, 550 Barchetta, 456 GT, GTA; BMW - 3, 5; AUDI - A6, A4