- Oxygen, Lambda Sensor
- Exhaust Oxygen Sensor (O2 Sensor)
- Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture
- Delphi "ES21291-12B1" - Not available
VW - Passat, Golf, Touran, Jetta; SEAT - Leon, Toledo; AUDI - A3, A4; SKODA - Octavia