2005 engine swap question

[The New Kid]

I have an 05 wagon and want drop an 07 sti engine in it
Wil I have any problems
Thanks

[Modena1230]

You will need the sti wire harness because the sti is drive by wire. I've heard its very difficult to swap.
RM

[The New Kid]

Do I need the sti tranny or could I run it on the 5 speed
It will fit though right

[newtothegame]

Not only the wiring harness, if I recall since one is drive by cable and one drive by wire you need to change pedals also. Im not sure about the transmissioni.

[Chase]

Putting an STi bottom end on WRX heads is a much more desirable choice, it makes the swap easier. Search hybrid block on here. You could continue to run your 5 speed either way, you just need a WRX clutch between them.

[The New Kid]

Well the problem is I have blown engine the top and bottom are no good so I need a whole engine and I want 2 upgrade to 2.5 sti engine and I found 2007 one for good price so dats y I am asking the questions and only thing I am really worring bout is if I am going need the transmision but chase it doesn't matter and from ### has been posted it going be diffcult swap but needs 2 be done

[oldfartracer]

You can't drop an 07 sti motor into a wrx with a ton of work. Harnesses, pedals, ecu, are just a few of the things needed. I think you have swap the motor harness and the body harness to get the STI ECU to work.
Buy the STI motor, sell the heads, get wrx heads. This would make life a lot easier.

[The New Kid]

ok i just talk to the guy its not a sti engine its 2.5 wrx engine but it does not come with ecu has every thing else including wiring harness can i use my old ecu or no

[oldfartracer]

No.
It might work if you swap out the intake manifold and TB from the 05.

[The New Kid]

so i have to buy a ecu for a 07

[The New Kid]

btw thanks for the help i really need to her running again