im new to this so here i have a 97 mustang gt with 110,xxx miles on it. car has cai, 70mm tb, off road x-pipe, 2.5 in pipes with flowmasters, screamin demon coils, livewires spark plugs wires, new plugs about 200 miles ago, fuel filter when plugs was put in, mass sensor about 1000 miles ago. pi head swap done feb of this year. Car has a sputter about 4000 to 4400 rpms when its 75 degrees an up outside. this morning it was about 63 degrees it did not sputter. does not do it during winter only summer. fuel pressure is 32 idle and 42 with vac line off. so i need some help to find out whats causing the sputter.