Carbon Monoxide is a product of incomplete combustion caused by lack of air in the air/fuel ratio.

Your car is running rich. The high Hydrocarbon reading is unburnt fuel because the engine is not running efficiently.

I would sugest you first try and weaken the mixture.

If you have access to a three gas analyser you want CO as low as Possible, HC as low as possible, CO2 as high as possible, (14.6 being ideal)

Good luck

RDA