2005 rs 2.5 into my 98 legacy gt

[joemcfarnham]

will a 2.5 from a 2005 imprezza rs fit into my 98 legact gt if not what modifications are needed? is the 2005 engine better in terms of gasket problems and such?

[SilentRacer]

yes and yes

[decke48]

wiring is the issue. you can use your harness with it. but you need to wire to the different injector, IAC, ect.. and the other problem is i dont know if they made the 05 n/a 2.5 drivebywire. it elminate the IAC and controls idle with the throttle. if it has no IAC on the manifold (05) you would need to use a older 2.5 sohc throttle boday that has the IAC build in. other than that idk the 05 have a EGR so you might have problems with that. there is a way to wire a resitor in the EGR solinoid. to elminate the check engine light.
i know the 05 legacy 2.5 n/a motor have problem with oiling, not sure about the RS motor

[Wiscon_Mark]

The 05 RS was not Drive by Wire, so that's one less headache.

I would swap engine harnesses and use the 05 RS ECU, it would probably be easier. More work, but less headaches in the long run.