hpfp not passing 1500

Hello guys, I have a 2007 Mazdaspeed 6 that can't pass hpfp 1487 at WOT, this is what i've done so far to try to fix the problem: *switch the whole HPFP borrowed from a friend (I have corksport fuel pump internals in my hpfp in good shape, no scuffs or anything in the internals) *in tank fuel...