[stephen low]

Running rich if my chemistry is right there Mando.

THC -Total Hydrocarbons would be a measure of the unburnt fuel being belched out of the system I'm guessing.

Not sure how it then relates to carbon monoxide though and even what the cats are meant to help reduce.

I'd presume a decent tuner should have some similiar analytical gear so get a reading before any retuning of the engine. This will benchmark your output based on their gear and will simplify comparing any further tuning and results.

Bad luck though on the results.