Mot Fail high emissions

My beloved hijet 2000 model mini bus just failed on high emissions. exhaust hydrocarbon content high after 2nd idle. carbon onoxide high after 2nd fast idle.
has anyone any suggestions as to where I might start looking for repair?
all help is appreciated.

I will also add that it is a 1300 cc engine.

Hello, I have the same problem, carbon monoxide too high on 2nd fast idle, did you end up getting any further with what was causing it? These are some of the checks we are going to do.
- Check/replace spark plugs
- Removal fuel rail, clean injectors
- Check coolant temp sensor
- Check Map sensor
- Check Intake sensor
- Check TPC sensor
- Check Lambda sensor
- Do Engine flush