Aeromotive 14137 - 04-06 SUBARU 2.5L STI FUEL RAIL SYSTEM - Manual (Page 9)

39. Connect the AN-06 90-degree hose end to the return port located on bottom of the fuel
pressure regulator and a AN-06 straight hose end to the AN-06 to 5/15 barb return line
adapter fitting. Plan a route for the line between the fuel pressure regulator and the return
line fitting, measure the length of fuel line needed. See section titled Hose and Fitting
Assembly for fuel line assembly instructions. Once the hoses are assembled, ensure
there is no debris in the hose and install it.
40. After installing all the fuel lines, the system should look similar to below.
Ensure the any spilled gasoline and any gasoline soaked shop towels are cleaned up and removed from
the vicinity of the vehicle!
41. Reinstall any electrical wiring, vacuum lines, fuel lines and throttle body components that
where removed for the original fuel rail removal.
42. Refill engine coolant and check system for leaks