My 2000 Legacy sedan stopped running recently. There were no CEL codes but it would not restart. I towed it home, checked the fuel pressure and found no pressure but some flow. With starting fluid or carb cleaner sprayed into the intake it would start briefly. I bough a new pump (Bosch) and installed it in the tank assembly. It would not start. There was flow, but no pressure. Hmmmmm....Just to be sure and thanks to Joe a local Sub mechanic we checked the cam timing, TPS, fuel injectors and vacuum lines. We bypassed the fuel pump and ran a line directly from another pump to the rail. It started! Turns out the fuel pump assembly has a chamber with an "O" ring. The cover to that chamber broke letting out pressure and most of the flow. It was difficult to see but the cause of the problem. I replaced the assembly with a Subaru OE part. I considered and Airtex assembly but there was no cost advantage. She runs great now but I did have to adjust the TPS for at 1507 code. I'll check the pump assembly from now on before replacing the pump.