This shouldn't be too tough to get right. The CO is a measure of how your car is set-up. In this case rich on both the idle jet and the idle mixture settings. I'm assuming a stock T3, so the first thing you need to do is check to see if the idle jets in the carb (s?) are the correct ones. If they are larger than stock, wuh-hoo, there's the cause of the high CO on the dyno. Remember, jets may be drilled.
If you dial the mixture screws in a bit, I think the driving CO will also drop, so make an adjustment there.