03 mustang gt hesistent idle 1500-2000 rpm

[svtcobra03]

just put a bbk throttle body intake (78mm) and sct custom tune on my car.
not sure if one of these could have caused it but after i put the mods on my car started to run funny when cruise in this rpm range.

[Cheezebandit]

tried talking the tune off and seeing if it helps ..?