The engine light is permanently on in my Ford Ka and using an EOBD reader I have the fault code P0171(Mixture too lean) I have checked all hoses for leaks,it has a clean air filter and new plugs. I am trying to avoid a costly trip to the garage so they can charge £50 just for using their diagnostic equipment.

I assume the next step is somehow testing the two oxygen sensors either side of the cat.

Any help would be appreciated

Maturecheese, May 2009

Have you tried resetting the fault code?

David, May 2009