Failed MOT emissions carbon monoxide

Hello, my pride and joy hijet 1.3 2000 van failed its MOT on emissions, carbon monoxide CO too high on 2nd fast idle. Does anyone have any idea's on what might be causing it? Any help would be appreciated!

hi - ive just joined the forum. My Hijet was very close to failing this year, im sure it'll be worse next year too. Did you get any luck with finding the cause, or reducing the readings?

To make sure your emission are correct, you have to make sure that your engine is in good order. Good engine compressions, new spark plugs, correct valve clearances and a new air filter. Make sure the exhaust has no leaks and give the van a good, long run and get the engine hot prior to taking it for the m.o.t.

Could try blasting some seafoam through it to help reduce carbon deposits

good advice there, thanks guys i'll try all of that