Want to install a 99 ej22 phase 2 non egr engine into a 2004 Impreza  with a ej25 egr engine. Is that a direct swap or will there be ecm issues?

have the 99 engines drivers side head drilled and tapped for EGR.

 

Then use the 2004 Manifold.  Might want to swap Cam and crank pulleys to match whatever type the 2004 needs.  99 might or might not be the same.

 

You could run it without EGR.....no real driving issues, but it will throw an EGR code most likley.

You need the EJ22 exhaust manifold.

 

Swap crank gear and drivers side cam sprocket or verify they’re the same. There’s two styles of triggers on the gear/sprocket.

 

EGR Id ignore.

You need the EJ22 exhaust manifold.

 

Swap crank gear and drivers side cam sprocket or verify they’re the same. There’s two styles of triggers on the gear/sprocket.

 

EGR Id ignore.

 

I don't know if WA state has emissions inspections or if they check for codes/monitors not ready during testing.  If not, ignore the EGR issue if they do then a work around for the EGR will need to be installed.  I do seem to recall where others had done a rework that did not involve drilling and tapping the cylinder head, but don't recall the method.