Um, lemme put in my .02, Chris.
The only way the computer knows what temperature the coolant is at is by the coolant temperature sensor. The
only way. Now if that sensor is going bad, but its signal is still within acceptable limits, the computer is going to say, "fine, the engine is at -10 degrees" even though it might be 70 degrees outside. You'll only get a code if the sensor is out of preprogrammed limits, and that's 90% of the time what happens. I think if it IS the CTS, then he's got the last 10% covered.
I had a customer with a similar problem. It'd run like crap when cold, then fine soon as it warmed up. Bad temp sensor.
95mustanggt: I think you're on the right track (possibly an ACT), but you should do some more testing. I'd pick up Charles Probst's book on Ford EFI and dive into it. There's a great section on testing sensors, and it's a tremendous asset to any DIYer or Mustang fanatic. Hope this helps.
------------------
Capri306, Moderator, The Mustang Works Online
"PROUD TO BE AN AMERICAN!!!"