i just bought a Honda with 2 fuel pressure regulator with a aftermarket fuel rail. One FPR is adjustable and before the rail and the other is the oem one on the rail. The air hose is connected to the oem one and not the adjustable.

So my question is should i leave it like that or should i eliminate the oem one and move the adjustable one after the rail?

 

The vacuum hose allows the FPR to adjust the pressure based on RPM or throttle input IIRC. Running no vacuum and just seeing atmospheric pressure it reads a constant higher pressure. Connect it up.

 

So should i buy a T fitting and split the air hose to feed both FPR or just switch the air hose to the aftermarket one before the fuel rail?

 

Why are there 2? Pick one. Remove the other.

 

Just run 1 after the rail.