Originally Posted by radd269
Yes the fuel pump in a WRX is bigger than the 2.5i you will need the harness for this as it is completely different for a wrx. To be safe, I swapped it out completely, also putting a Walbro in it's place.
I also dont know about the '08 2.5i, but the 06 2.5i only has 2 fuel lines, and the WRX has 3. I would look into that as well if I were you. Also make sure you have the fuel controller as well.
It looks like the ABS unit is also significantly different. I got the controller from my source car(manual, w/turbo), but are any of the lines different?