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Engine management light is on – what’s the fault?

I own a 2008 Vauxhall Corsa SXi, which has only covered 12,000 miles. After its last service and MoT the engine management light (EML) came on. I changed the front O2 sensor, but after 48 hours it came back on.

Stuck for ideas, I took the car to my local dealer and they a EML 1 code P0171 fuel trim malfunction bank 1. They reset engine ECU suggested changing fuel type, which I did. However, after 48 hours the light came back on.

I have now been told there could be seven possible causes: exhaust, inlet, EGR, fuel tank vent, O2 sensor, and map sensor. The garage has changed the rear O2 sensor and replaced the breather hose, but the EML light still comes on. Can you help? I’ve spent over £600 and am no closer to finding the fault.

Asked on 28 August 2013 by Laurence Raven

Answered by Alan Ross
A very difficult code (P0171) to identify as it is indicating that the fuel system is running lean.

It could be air/vacuum related so all pipes /hoses need checking first. After that it could be as said one of many things, but we would have thought that the garage would check out each item separately before changing it,therefore saving the cost of parts.

I would suggest that you go back to the dealer and ask to speak to the service/customer manager(or general manager) and tell him that you are not satisfied with the level of repairs carried out so far and that you need the car working correctly at no additional cost.

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