The excessively rich running seems to suggest the CTS under #2/3 inlet tracts on the head. Bosch 0 280 130 032 or 039 or 069 are the OE part numbers. I used an Intermotor one on my V6 and haven't had any of the alleged problems others have had using non-genuine items.
If you have a multimeter, check the CTS cold. Unplug the connector and (making sure you manage to check both pins) test the rsistance to the head which should be ~2500 Ohms +/- 10% @ 20C.
Given that it's colder than that at the moment, expect the cold readings to be ~3k Ohms from each pin to the head and as a final check, test between both pins which should be the sum of the two figures from each pin to the head.
Also sort that air leak as well!
