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2.5L to 2.2L swap

Posted: Tue Sep 18, 2018 6:09 am
by jermanbetts
I have a 98 legacy L. Hit a deer and killed it and my car. I also have a 98 outback that has a 2.5L removed due to headgasket leak. Id like to put my 2.2 in but im told that you need to swap the harness as well. Is this accurate and what does this involve or even worth the effort

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Re: 2.5L to 2.2L swap

Posted: Wed Sep 19, 2018 12:11 am
by mike-tracy
1995-1998 Legacy ej22s are a direct, plug compatible swap. You should grab the ecu from that ej22, or your car will have harder starts, and get worse economy than normal. Most of those have single port exhausts, so you'll need to grab the headers. It bolts up to the rest of your existing exhaust.


1990-1994 Legacy and 1993-1998 Impreza ej22's could work, but you'll have to swap over a 1995-1998 Legacy 100% complete intake manifold and engine sensors. Probably not an option unless you have a ton of subarus in your junkyard.


1999 Legacy ej22 as well as 1999-01 Imprezas got the new manifold, heads and wiring, not worth rewiring your car over.


Last but not least. If you have an automatic, you need reuse the 2.5L flex plate and torque converter. They have a different bolt pattern than the ej22's flexplate/tq converter. I learned that the hard way, after my engine was back in and bolted up. :evil:

If it's a manual, then the 2.5L clutch setup works with the 2.2 no problem

Re: 2.5L to 2.2L swap

Posted: Wed Sep 19, 2018 1:35 am
by jermanbetts
Thanks for your input. So the 1998 2.5L wiring is the same as the 2.2L?

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Re: 2.5L to 2.2L swap

Posted: Wed Sep 19, 2018 2:16 am
by mike-tracy
Only if you follow the years and vehicles I mentioned for the 2.2L. Otherwise, no.

Re: 2.5L to 2.2L swap

Posted: Wed Sep 19, 2018 9:01 pm
by wtdash
Just to add to Mike's most excellent info.....

.....the 2.5 to 2.2 swap is (or was as these cars are getting OLD) done A LOT due to those crappy 2.5 HG and rod bearings. Search on line and check out the https://www.ultimatesubaru.org site for LOTS of info.