I would be interested in the answer too. My MOTs are done at ATS and they no longer automatically provide the emissions report on an MOT pass. I find the report useful as a guide to general engine health, not so much CO but certainly Hydrocarbon. The MOT pass of 200ppm is way too high for a healthy engine running correctly; it has been a long time since I have seen figures as high as Johnos, something very obviously wrong with that car, I’m sorry to say. Hydrocarbon is unburnt fuel at the crudest level, so that car must be using a lot of petrol if oil level not dropping.