Change the oil and oil and air filters and give the car a fast run to get it throughly warmed up just prior to the MOT test-I assume the test will be by appointment while you wait .

These measures may make all the difference!

Singlish

My MOT is due soon but i am concerned because although my car passed last time, the fast idle C O emission was 0.2% which is top of the limit allowed.

The natural idle test was well in at 0.04% (0.3% is the max limit)

The Lambda value was1.014 (0.97-1.03 range allowed)

Any suggestions how i can improve my fast idle emissions please?

Thanks for that Singlish.I should have said that i did all the things you suggested prior to my previous MOT