Another thing I'm considering is the K&N. I've had the Mach 1 for a month, and never had it stall before. Put in a new K&N, and then it happens two weeks later. It could be a coincidence.. I even wiped off the K&N with a rag too.
sorry I didn't answered sooner, since I'm travelling right now. A day before leaving my city I went to the shop to pull the codes out.
Before telling you the new codes, I should tell you that before changing the IAC the computer threw these code1443 Evaporative Emission Control System - Vacuum System - Purge Control Solenoid or Purge Control Valve fault.?
Now after the IAC has been changed these are the new codes that appear:
P1443 Vacuum system purge or VMV fault
P0175 System too rich (Bank 2)
But the problems or symptoms are the same.
I'll answer back to whatever suggesionts as soon as I can.
By the way it's an automatic tranny.