Subaru Forester Owners Forum banner

1 - 20 of 20 Posts

·
Registered
04 Forester
Joined
·
29 Posts
Discussion Starter #1
Greetings,
I threw a rod in my '03 Forester, so I decided it was time for an upgrade. I found an '06 EJ255 with low miles that I purchased and I have ready to swap in.

I still need the proper ECU and to swap out the wires - in progress.

Before I undertake this task, I need to clarify whether or not I will need to swap out the pedals. I'm thinking that the '06 WRX was drive-by-wire, and determines how far to open the throttle body by the ECU based on the position of the pedal.

Is this correct? Has anyone on here swapped an EJ255 into the prior generation forester?

I'm taking lots of pictures and plan on fully documenting this swap. Any assistance/advice would be greatly appreciated.
 

·
Registered
2002 S
Joined
·
2,702 Posts
I did an 04 STi(DBW) swap in my 02 Forester(DBC). You need to get the DBW pedal for the swap to function. To simplify your life, I would also look into picking up a DBW pedal adapter from East Coast Swappers as the DBW pedal mounts differently than the cable one.
 

·
The Sub kit guy
2005 Forester X & XT VF39
Joined
·
13,100 Posts
If your doing the full swap and your car is an MT, you might want to think about getting a VF39, STI TMIC and an 04 STi ECU. They you would basically have a stock STi setup.
 

·
Registered
04 Forester
Joined
·
29 Posts
Discussion Starter #8
I just ordered a FMIC and was about to get the corresponding EJ255 ECU. Why get an STI ECU? Obviously it's mapped differently, but what would be the benefits? Wouldn't that require some significant tuning when compared with a newer gen WRX or XT ECU?

That brings me to my next question: What is the process for flashing an ECU? I've read about USB - ODBII cables to do it manually. Anyone have experience with these?
I know its an anti-theft measure. Can I take the ECU by itself somewhere to have it flashed to work with my current ignition?

Currently I'm still working taking the dash apart - some of those dash trim screws are really tough to access! Let the adventure begin!

It's so poetic - Valentines day and I'm bout to rip her broken heart out.
 

·
Super Moderator
2007 Forester Sports XT 4EAT
Joined
·
35,959 Posts
Yes, i am sure. I tried to post the picture up, but I have to have >15 posts. Let me go spam the board elsewhere real quick...
You're required to have 15 posts to link to a host (to prevent spamming), but you can attach pictures (thumbnails) now. :wink:

Bobby...

My MODding Journal
 

·
Official sf.org decal guy
2006 FXT
Joined
·
12,516 Posts
Why get an STI ECU? Obviously it's mapped differently, but what would be the benefits? Wouldn't that require some significant tuning when compared with a newer gen WRX or XT ECU?

They are commending an 04 Forester engine because it is the exact same as the 04 STi. You can swap in a VF39, STi IC, and other bits along with the 04 STi ECU and be running the exact same setup as an 04 Impreza STi (no ECU programming needed).

If you get the 06 MY ej255 and put the power bits on while the engine is still out (as you should), you're going to have to get the 06 ECU retuned.
 

·
Registered
04 Forester
Joined
·
29 Posts
Discussion Starter #11
Probably not going to have the funds to swap the turbo at this point. Maybe at some point.

It seems like I am going to have the ECU tuned, whether it is an EJ257 or EJ255. Initially, is the ECU going to require a flash to make it function with my current ignition?
 

·
The Sub kit guy
2005 Forester X & XT VF39
Joined
·
13,100 Posts
Does he need and 06 ECU to run the motor, or can he use an 04? The 06 ECU would have the immobilizer stuff, and I think you need to key switch and all that from the same car to get it all working together. Since the 04 didn't have an immobilzer, he wouldn't have to switch all that out.
 

·
Registered
04 Forester
Joined
·
29 Posts
Discussion Starter #15
Next question - does the 04 or 05 STI ECU connect to an 06 dash wiring harness?
To my understanding the 05 STI does not have an immobilizer key, so it should just fit right up with my current ignition.
Also, I found an '04 STI and an '05 XT at a salvage yard. Would using either of these ECU's require flashing, or merging? I'm wondering which one would be best... Obviously the STI for power additions later down the road, but I'm just trying to foresee which would be the most compatible.

I received pedals from an '06 DBW WRX and the dude packed it horribly. The accelerator pedal was not connected anymore... Must have been a kid, or just an idiot. Hopefully it wont cause any problems, but obviously pedals are critical for safety and functionality.

Sigh...
 

·
The Sub kit guy
2005 Forester X & XT VF39
Joined
·
13,100 Posts
The 05 STi and XT have immobilizers.

The 04 STi and 05 XT ECU will plug in to the 06 harness, but you will need to repin 5 or 6 wires to use the 04 ECU. They moved a few wires around to prevent a theft from just plugging in an 04 STi ECU into an 05-07 STi and circumventing the Immobilizer.

This thread has good info related to what your doing:

2005 STi immobilizer question/ Engine in a non-Subaru chassis - NASIOC

I think an 04 XT ECU would be your best bet. You would have to repin a few wires, but that's better than trying to find all the matching parts to use an 05+XT or STi ECU. An 04 STi ECU would work, but you would need a remap since it was designed to run with the STi TMIC and VF39.
 

·
Registered
04 Forester
Joined
·
29 Posts
Discussion Starter #17 (Edited)
Excellent information. Unfortunately, the 04 XT harness isn't one of the options - but it would definitely should be the best option - at least the most flexible.

I'm thinking though, that since the 04 STI ECU and harness available then I it may be best to go with it. Also, I may have found a turbo off of an STI to stick on my new engine!

Trying to post pictures....
 

·
Registered
04 Forester
Joined
·
29 Posts
Discussion Starter #19
Update: Found an 04 FXT wiring harness. I'm hoping it will plug right up to the engine wiring harness - I'm getting some pictures of it.

Engine is out - pulled off the a/c, power steering, alternator, and the heads. I can definitely tell from the conditions of the plugs and hoses that the car has 120k miles. Otherwise, it looks pretty good. Anyone interested in some SOHC heads?

Almost to my 15 post requirement so I can post up some pictures.
 

·
Registered
2008 Forester XT
Joined
·
20 Posts
Why not just run the cable? thou I guess that with the conversion your doing you would have to change a lot of wiring anyway so a pedal box isn't really that much extra hassle right?
 
1 - 20 of 20 Posts
Top