hi

Ive got a 2006 hawkeye wrx Estate standard apart from a prodrive upgrade and it keeps throwing up a lamba sensor fault on bank 1. Sensor has now been replaced twice once with a non genuine aftermarket sensor 2nd time genuine subaru dealer supplied sensor. Replace the sensor and the car runs great for about 60-100miles then ping lights back on same fault. Any ideas??? its done 71000 miles always been regularly serviced and looked after.

when the lights on it drinks fuel and is hesitant on acceleration. light off and it's exactly how it should be. So its definetly a sensor fault not a mechanical issue.

Thanks Rich

Wiring issue?  I can't see you killing a lambda sensor in 100 miles no matter how bad your engine was.

You could be getting a code up for lambda sensor due to a fuelling or spark fault causing the lambda readings to be out of the maps parameters.

 

Check the coilpacks for cracks in the insulation and see if the spark plug colour /condition give any tell tale signs of a misfire or fueling issue.

 

Could be something simple like a dirty air or fuel filter altering the afr readings

 

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