Hi Alan,


I think you are on the right lines. As you know the Lambda reading incorporates 02 and I can remember many occasions (in pre-cat days)I used to create an air leak to get a vehicle through an MOT test. I am not a MOT tester incidentally. With the Lambda reading this is no longer possible with a vehicle that has to meet the more stringent test. However, what galls me is that I have attended vehicles with failed Lambda readings because the owners did not realise they had an air leak. So in effect the vehicle has failed the MOT test not because it is polluting the atmosphere, but creating too much oxygen!

Regards

Pete M