Radium Engineering 08-17 Subaru WRX STI Fuel Pressure Gauge w/ 8AN ORB Adapter

• USDM 08-21 Subaru WRX STi (EJ257 only)

This kit replaces the OEM fuel pressure regulator and damper assembly. The factory STi fuel line routing uses a quasi dead-end system that circulates fuel through the regulator, bypassing the engine. Fuel is only routed to the engine when there is demand.

The Radium FPR kit reroutes fuel to cycle through the fuel rails before reaching the regulator and returning to the tank. This is the preferred fuel line routing by Subaru tuners trying to address stumbling issues. The kit installs in the same location as the OEM fuel pressure regulator. Also included are vacuum hose and fittings to reroute the vacuum reference line from the #4 cylinder runner to the intake manifold plenum for a more stable vacuum signal. The optional pressure gauge kit 20-0386 (sold separately) can be installed into the unused 8AN ORB port on the regulator.

The regulator features the first tool-less pressure adjustment. A jam nut and set screw are no longer required. With a simple turn of the knob, pressure will be increased or decreased.