Ok, techies .... one for you ....

My other car, a 1995 MX5,:-

CO reading last year at idle is 0.3% (limit is 0.3%) it has been increasing each year for the past 5 years.

From 0.07% - 0.3% ..... I am sure this years MOT will see it at 0.32% or something ..... hence a fail!

Lamda reading has been 0.993V each year so thats fine

HC are well withing spec

CO reading at fast idle is a pass (but this has been increasing to!)

Would replacing the Lamda sensor cure it? Is it a new CAT thats required?

The engine runs and idles perfectly, no misfire, no hesitation, the car does 1200miles a year! (could that in itself be an issue?)

Cheers for any reliable hints and answers

Pete

 

Hi Pete. Sounds more like the cat to me. The lambda reading would be off if the lambda sensor was dodgy. Might help giving the car a really good drive before the test to get the cat nice and warm.

 

Thanks John .... not what I wanted to hear really but thats my thoughts exactly!

Maybe a nice long hard run would just pull it through? Anyone any legal ideas?

Pete