pulled codes? at part throttle, the EGR should be functioning. if it is malfunctioning, that could cause some havoc (or if it is runnin intermittantly at part throttle, which would be incorrect).
what is your vac reading like? a healthy stock-ish motor should have around 15-20inches at idle. under WOT, almost zero. at part throttle, somewhere in between.
while i think Morris has good stuff to say, i dont agree with him on this one. if you are running decent at WOT and idle, i would not necessarily have thought of the Fuel pressure being an issue.
that said, im not real bright, so: the stock FPR is behind the TB. it is not adjustable in stock form. an adjustable unit is the easy way to dial in more pressure. i dont see mods in your sig that would justify such a purchase. if you pull the vac line on the FPR and find fuel in it, then do replace it - that is a sign of a bad FPR (bad diaphram).
my ramblings. good luck.
