Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture StartVOLT "VS-OS 0504" - Not availableCHEVROLET - Aveo, Lacetti, Nubira, Rezzo, Kalos, Spark; DAEWOO - Lacetti, Kalos