Thanks for replies and know this is a very delayed one.........
Not sure on the blow by gases to be honest.
Problem is high hydro carbons and carbon monoxide. Have read that high CO levels can be caused by old spark plugs, crap oil and blocked air filter as written above. All of which changed a week after the MOT so might be worth it being checked but not sure how much difference those items would make.
The guys that did the mapping said the fuelling at idle and constant throttle wasn't changed.
If no one else with this Kam system has had the problem then I know it's the ca