I have a 96 mustang gt and i swapped the old intake for the pi intake manifold, i got a mechanic to install the intake and use all the stuff that came with it. I did a tune threw my SCT tuner and the car runs well but sometimes runs alittle rough at the beginning of first gear. My mechanic thinks its the air control valve , he things that i need the one from a 2001 gt mustang since the pi intake manifold came from that mustang. Can anyone on here tell me if he is right or do i just need to replace the old 96 gt air control valve.

 

Can you describe "runs a little rough"?
Is it hesitating, missing,ects....?

 

it is hestating big time , feels like its bogging , not a miss fire since my mechanic checked that all out , including plugs , wires etc....

 

The thing is that the IAC, which i thing you mean usually makes the idle hang high for a bit before it comes down when you come to a stop. That is what most of the muustang guys expirience when these things start to fail or get real dirty with carbon.
Double check all the connections that were disconnected during the swap.
This guys found his issue, and it was something really simple that no one would think off.
Read the text in red.
2000 GT, 4.6 low RPM hesitation misfire skip PROBLEM SOLVED! - MustangForums.com

 

More tech help...
98 Mustang GT 4.6 / Hesitation, while cruising between 40 -70 | Mustang Forums at StangNet

this is with the coil on plugs, but same syptems would happen with coil packs and wires.
2000 GT Rough idle + hesitation around 1500-2000 RPM | Mustang Forums at StangNet
Did you replace the plug wires?, or try diffrent coils?

Also, have you checked to see if your are reading any codes?

Seems that most hesitating issues are caused with fuel, or spark when i do a search on most stang boards threw google.

 

Well same problem I am facing that's why I attract toward this thread, this is really interesting...

 

Nice 1LOW03GT.