I just registered but I've already lurked and fixed an issue with my recently purchased 02 GT.
I was having an intermittent woodpecker like banging under the hood and found it to be the IAC.
Cleaned that bad boy up and no more noise.
OK, I was wrong. It didn't fix the problem. It helped but there is still an intermittent noise coming from the intake.
After research I've decided to find a new IAC out of a junk yard. OEM Motorcraft Part # CX1785 are over $100.
Generic replacement parts don't cut it here either since the resonance value of the IAC motor is specific and will continue to make noise if not used.
Just FYI for anyone else who gets this strange noise.
PS: Idle is fine too, just a weird hollow banging