OK So I'm stealing the thunder of other peoples work but I did the research for you and here it is.
All cars will need to have a fuel filter that can be changed. It is a part of ever vehicles routine maintenance. For an 04 STI, it should be changed every 60k miles. Here is a link to the 2004 STI maintenance schedule:
SUBARU.COM : TOOLS : 2004 <---click the link at the bottom of the page
The fuel filter (not to be confused with the 'fuel sock' that is in the bottom of the fuel pump assembly):
Subaru OEM STi/WRX Fuel Filter IA Performance
This is a link to a step by step fuel pump assembly removal DIY:
Walbro Fuel Pump
Here are the links to the actual fuel filter removal instructions:
http://www.scoobymods.com/forums/att...2&d=1176947664 <--READ THIS!
http://www.scoobymods.com/forums/att...9&d=1086023008
http://www.scoobymods.com/forums/att...0&d=1086023402
http://www.scoobymods.com/forums/att...1&d=1086023411
http://www.scoobymods.com/forums/att...2&d=1086118138
http://www.scoobymods.com/forums/att...9&d=1091888479 <--READ THIS!
Info on Subaru fuel system:
http://www.scoobymods.com/forums/att...3&d=1183634563
http://www.scoobymods.com/forums/att...4&d=1183634580
http://www.scoobymods.com/forums/att...5&d=1183634645
All cars will need to have a fuel filter that can be changed. It is a part of ever vehicles routine maintenance. For an 04 STI, it should be changed every 60k miles. Here is a link to the 2004 STI maintenance schedule:
SUBARU.COM : TOOLS : 2004 <---click the link at the bottom of the page
The fuel filter (not to be confused with the 'fuel sock' that is in the bottom of the fuel pump assembly):
Subaru OEM STi/WRX Fuel Filter IA Performance
This is a link to a step by step fuel pump assembly removal DIY:
Walbro Fuel Pump
Here are the links to the actual fuel filter removal instructions:
http://www.scoobymods.com/forums/att...2&d=1176947664 <--READ THIS!
http://www.scoobymods.com/forums/att...9&d=1086023008
http://www.scoobymods.com/forums/att...0&d=1086023402
http://www.scoobymods.com/forums/att...1&d=1086023411
http://www.scoobymods.com/forums/att...2&d=1086118138
http://www.scoobymods.com/forums/att...9&d=1091888479 <--READ THIS!
Info on Subaru fuel system:
http://www.scoobymods.com/forums/att...3&d=1183634563
http://www.scoobymods.com/forums/att...4&d=1183634580
http://www.scoobymods.com/forums/att...5&d=1183634645