Have 1999 Legacy Obw with ej25 dohc engine with bad head gaskets. Can I swap in either the ej22 phase 2 or the ej25 sohc engine. I know the wiring harness attached to the intake manifold of the ej22 phase 2 and the ej25sohc are different from the wiring harness in the car now. Therefore can  I use the ej25dohc intake manifold/wiring harness on the ej22 phase 2 or ej25sohc engine? That way the harness will match whats in the car now.

 

To restate my question. Does a ej25dohc intake manifold attached to a ej22 phase 2 or a ej25sohc engine  work correctly in a 1999 Legacy obw that had a ej25 dohc originally in the car.

the ej25 dohc intake will NOT bolt on to a phase 2 engine.

 

it will not swap.

 

try again.

Well that clears that up. I have been swapping in ej22 phase one engines into the 1996 to 1999 obws. I guess that my only option. Its a good option though. I was just curious if there were any other options. The ej22 phase ones are getting harder to find with low mileage . I really don't like redoing head gasket on ej25dohc engines. I've bought quite a few 1996 to 1999 obws that have failed twice and the sellers just wants the car gone. Its been my experience that ej25ds are more trouble than there worth. 

Edited October 29, 201510 yr by steve56

I just put a phase 1 ej22 in my 99 OBW. I used the wiring harness off the ej25d intake on an old egr ej22 intake I had. Worked just fine, I don't know if it would work with what your doing but if it works phase 2 ej25d to phase 1 ej22 I don't see why it wouldnt work.

Unfortunately the 1999 ej25d is a phase 1 engine. So yours swap was all phase 1 parts. The phase 2 uses some different sensors like map instead of maf. However I'm hoping  there are only  a few work around issues to overcome. I haven't found out what they are. Hopefully someone here has used the ej25d intake manifold wiring harness on a ej25 phase 2 engine. I don't want to swap it in and find out I wasted my time. 

idling is one issue as the idle controllers aren't the same/compatible.  propping the throttle open is one work around but cold starting is problematic. 

 

Gloyale has posted a good description of the after-effects, look for his comments to see if that was phase I to phase II or the other way around.

a couple hrs with someone with a cnc and intake adapters would be ready to bolt on. Providing the spacing is identical.. Could cut 2 manifolds apart and have adapters tig welded out of them... The real answer is, swap the vehicles heads with the new short block.. Or could do Ej22e heads on a Ej251 block I'm sure. Not ideal but no CEL and it would run

 

Unfortunately the 1999 ej25d is a phase 1 engine. So yours swap was all phase 1 parts. The phase 2 uses some different sensors like map instead of maf. However I'm hoping there are only a few work around issues to overcome. I haven't found out what they are. Hopefully someone here has used the ej25d intake manifold wiring harness on a ej25 phase 2 engine. I don't want to swap it in and find out I wasted my time.

Mine was a phase 2, it had the eight hole block. Now I could see a 99 phase 2 ej22 working, but I've seen ej251 short blocks installed on older OBW, but they had to use the ej25d heads and manifolds. Aside from that the maf sensor is on a separate part of the harness its possible you could do a work around. Idle air control issues I could see, but that should be a fairly easy fix, if that was the only problem.

Edited October 29, 201510 yr by mikaleda

Mine was a phase 2, it had the eight hole block..

 

Yours is a Phase I engine for this thread and practical purposes.  This is intended for this thread/the OP to keep things simple.

 

99 OB's use Phase II short blocks but are Phase I in every other way - heads, intake, electronics.  So the OP needs to know he has an EJ25D (what most of us call Phase I) vehicle.  Not compatible with later EJ25 variants (what we usually call Phase II).

 

They are plug and play interchangeable with 1996-1998 EJ25D's.

They are not plug and play compatible with later "Phase II" (electronically) engines.

The odd one-year block distinction doesn't matter, and confuses things for a noob, since all the blocks are interchangeable anyway and interchange

is based on electronics and intake manifolds, not short blocks.

 

Since all 1996-1999 EJ25D's are easily plug and play interchangeable they are usually referred to as Phase I, even though that 99 year used one part that was a Phase II part.

 

The confusion comes from semantics - does Phase I & II indicate any part, a percentage of parts, short block, long block, or electronics?

Now I could see a 99 phase 2 ej22 working, but I've seen ej251 short blocks installed on older OBW.

 

those are essentially the same engines.  EJ22 Phase II and EJ251's are plug and play interchangeable - so approach is the same on either engine.  just like your EJ251 example - the Phase II EJ22 will work if you swap heads/intake/electronics onto it.

 

To clarify, OP can do the following:

 

Swap 99 intake wiring onto intake manifold, and work around idle/cold start issues)

or

Bolt 99 heads and intake onto short block

 

On any of the following engines:

99+ EJ22

99 Forester or Impreza RS EJ25

00-04 EJ25

 

And technically probably later EJ25's but those will likely be expensive and additional changes.

Good to know, these years are fairly confusing since they made so many changes in such a short period.

these years are fairly confusing since they made so many changes in such a short period.

 

indeed!  just about every year there's changes

96 EJ25 premium gas, 97/98 different valve cover gaskets, 99 Phase II short block, 99 Phase I and Phase II depending on model, 2000 Phase II across the board

EJ22: 94 OBDI, 95 OBDII, 96 single port exhaust, 97 interference and new tensioner (on most but not all 97's). 96+ EGR randomness and charcoal canister changes.