Got my o2 sensor installed. I think I've got everything resolved as far as the codes are concerned...

Did you ever change the fuel pump ?

not yet but looking into it. i keep getting the fuel trim bank 1 fault code. now why it keeps sending bank 1 and not bank 2 I don't know unless it only has "1" bank even though there are 2 heads and rails. how easy is that pump to get to? is it one I can access through a hole in the floor or do I have to drop the tank?

Change front O2 senser the fuel pump is super easy right behind the rear seat back on PS side is a cover with 4 screws then you can see the fuel pump cover I putt a carter HP pump in mine for a wrx is 260 lpr vs 160 lpr stock one part # P74152HP made a big diference in my 98 outback sport

change the front o2 sensor even if there isn't a code popping up for it?

 

Fuel trim is a o2 senser code o2 controls fuel trim. bank 1 is front bank two is rear