Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture OSSCA "41274" - Not availableAUDI - A4, A5, Q5, A6, A7; AUDI (FAW) - A4l, Q5; PORSCHE - Macan; BMW - 3, 4