Idle problem+ KB 9psi?

[01MustangGT]

i currently have an idle problem. it happened before when i still have the warranty, i think Ford give me a new IAC, and it was gone for 2 years. now it is back again. i drive on freeway at 2000rpm, then i step on the clutch, it jump to 22000rpm, then stay there for a few second, and drop back to 1000rpm. i stop at traffic light,the needle goes to 1500rpm. is there anyway to fix it?
I just ordered a KB 9psi. i will be at my door in about a week and a half. Will the installation of KB solve this problem? does the KB kit comes with the new IAC?
The damn 1500rpm+o/r H pipe + magnapack at traffic light is making me nut.
Thanks in advance.

 

[2001Saleen181]

Try resetting the ECU "Disconnect the Battery and press on the brake pedal". Let it sit for at least 5 min.

No the KB kit does not come with a new IAC.

Anytime you change the amount of air flow ie. Throttle body, Headers, exhaust you must let the computer re-learn to account for the new airflow.