so my engine management light came on about a month ago and a friend ran it through his laptop and it came up with the fault code P0420.

Which I think means its the lambda sensor?

either way I never got around to buying the sensor because I was on my stag do, then had to sort bits for my wedding.

The engine management light has now turned itself off, does that mean there isnt an issue anymore or does it mean the sensor is still dodgy?

Cheers!

 

I had the same problem on my scoob. It turned itself off after a while but came back on when on load up a hill for example. An easy fix swapping out the sensor but I never got around to it. The downside was it made the car run really rich and obviously buggered up my fuel economy

 

Do you what sensor I require? Its a 2005 blob eye sti.

Thanks