I am trying to get my car ready to sell, so needs an MOT. It has failed again today on emissions. The CO needs to be 0.2 and is around 0.4 at its' lowest. I had the same problems last MOT which was about 2 years ago, and the garage told me it was the cat. I had an aftermarket cat fitted (BM catalysts) which did not seem to make any difference. The car has covered only 300 miles since that cat was fitted. The garage finally passed it but did not give me any clue as to what they did and I can only assume they fiddled it. I have changed the oil and filter, air filter is like brand new and I have fitted a new Lambda sensor. Has anyone had similar experiences or got any ideas?
