Rover 416 failed MOT due to high CO emission

your CO level wasnt that high, which means there is probably nothing wrong with your ECU or any other sensor...............however unfortunatly it looks like your catalytic converter has given up. there were prone to premature failure but would sometimes pass if they were red hot just prior to the emmisions test. (i'm an mot tester myself) if the mot tester was a fair bloke he might have given you a second shot at the test to make sure the cat was really hot, even though the only temperature requirement for the catalyst test is that the engine oil temp exceeds 80 degrees. however a new catalyst will solve this problem instantly looking at your result figgures (guaranteed) the upside is that replacement catalytic converters are less than half the price they used to be since there are so many manufacturers making them now...shop around for one, but dont pay more than £150.00 excluding fitting.

one final note, just to correct your lambda requirements, this figgure should be between 0.97 and 1.03 but as you say yours was pretty good.

hope this helps.........

i said dont pay more than £150............read closely.........there are still companys that will supply a stainless steel one for over £200............ i dont doubt you can get one for £58.probably plus vat..probably plus delivery if ordering....and at the end of it all you'll get what you pay for.