will an aftermarket fuel pump (may need one for my nitrous) descrease fuel economy while driving normaly without engaging n2o?

I know i will burn more while nitrous is flowing but i am wondering if its gonna burn more while i am city driving and whatnot?

it shouldnt effect milage cause the computer is only spit out what it needs from the injectors

To a degree. Depends how much stronger the aftermarket pump is. If the fuel pressure is higher than expected it'll be thrown off. The ECU adjusts injector pulse width assuming a stock fuel pressure. Higher pressure will get more fuel through each pulse then expected. The ECU may compensate for that as well, by sensing the a/f ratio, but it will be a delayed reaction.

the fpr is what keep the pressure of the system , no matter if the pump is putting out 100 psi , if the fpr is only going to limit the pressure to 40-50 psi , the rest will get bypassed to the tank

[quote=97cavie24ls(JDM cav sedan™)]the fpr is what keep the pressure of the system , no matter if the pump is putting out 100 psi , if the fpr is only going to limit the pressure to 40-50 psi , the rest will get bypassed to the tank

yup