Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture OSSCA "41421" - Not availableAUDI - A3, Q2, A1, Q3, A4; SEAT - Leon, Ateca; SKODA - Octavia, Karoq; VW - Golf, Tiguan