On '98+ Rangers, the FPR is in the tank with the pump. So he might be talking about the "fuel rail pulse damper", which looks a lot like a small FPR.

I'm not familiar with the 2.3L so I don't know where the damper's vacuum hose would be routed on that engine. It should, however, be connected on the other end to the upper intake somewhere, because in the event the pulse damper diaphragm were to rupture, the fuel will be sucked into the intake and burned in the cylinders. That's the only purpose of the vacuum line - to avoid fuel spillage in the case of failure.