Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture NPS "DOX-1569" - Not availableOPEL - Astra, Vectra, Omega B, Signum, Zafira; VAUXHALL - Astra, Vectra; SAAB - 9-3