- Oxygen, Lambda Sensor
- Exhaust Oxygen Sensor (O2 Sensor)
- Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture
- FORD - Escort, Mondeo, Focus, Scorpio, Fiesta; AUDI - A4, TT; FIAT - Doblo, Punto; CITROËN - C5, Xsara; ALFA ROMEO - 156, 166