G3 Lambda Sensor - GTI

This heated lambda (oxygen) sensor is designed to fit before the catalytic converter, where it plays a critical role in monitoring exhaust oxygen levels and feeding real-time data to the engine control unit. Using this information, the ECU continuously adjusts the air–fuel mixture to maintain strong performance, good fuel economy, and correct emissions.

With a 4-circuit heated design, the sensor reaches operating temperature quickly after start-up, improving cold running and reducing emissions. A failing pre-cat lambda sensor commonly causes poor MPG, hesitation, uneven idle, engine warning lights, and MOT emission failures. Replacing it restores correct fueling and smooth engine operation.

Technical Details

• Sensor type: Heated oxygen (lambda) sensor

• Number of circuits: 4

• Fitting position: Before catalytic converter (pre-cat)

• Cable length: 990 mm

• Function: ECU air–fuel mixture control

Vehicle & Engine Fitment Summary

VW Golf Mk3

• 1.4 Petrol – ABD, AEX (10/1991–09/1994)

• 2.0 Petrol – 2E (10/1991–07/1995)

• 2.0 GTI 16v – ABF (08/1991–09/1994)

• 2.8 VR6 – 01/1992–09/1997

VW Corrado

• 2.9 VR6 Petrol – 08/1991–12/1995

VW Passat B3/B4

• 2.0 Petrol – 115 PS (Saloon & Estate)

• 2.8 VR6 Petrol – 174 PS (Saloon & Estate)

VW Vento

• 1.4 Petrol – 55–60 PS

• 2.0 Petrol – 115 PS

• 2.8 VR6 Petrol – 163–174 PS

Common Fault Symptoms

• High fuel consumption

• Flat spots or hesitation

• Rough idle or misfiring

• Engine management warning light

• Failed emissions test