hi my99 uk turbo impreza failed mot emissions. it has a wrx ra bottom end fast road pulleys from graham goode racing autronics ecu, scorpion stainles steel centre pipe and back box. its has a cat on the downpipe and lambda sensor fitted.it does not have the centre section cat only the down pipe one. the mechanic said it was no where near to the pass rate. any ideas what it could be?

 

maybe look for second opinion mate, who knows it might pass

 

agree,after reading alot of these lately,one place says wow,its failed,others will pass it and say its fine

 

What exactly did it fail on? CO? Lambda? Both? The operator should have given you a printout with the details on - and anything you can tell us will make guessing a little more educated.

There are any number of potential causes, from a knackered main cat to your ECU simply not being mapped for emissions compliance. The second opinion idea is a possible but beyond that, might be worth a word with the mapper. And tell us about the numbers from the test.