Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture Elta Automotive "EX0381" - Not availableSEAT - Cordoba, Ibiza, Inca; VW - Caddy, Polo; AUDI - A4; CITROËN - Xsara, C5