Does anyone know if I can replace my 98 Outback's (2.5l automatic) ECM with an ECM from a 97 5speed Outback?? Is there any compatibility issues here, or am I good to go?

If you want to be 100% sure get one with the same numbers on the computer. If you will check with Rock Auto you can get them cheap if they have your number, go to their web site they have a really good and fast parts catalog.

Does anyone know if I can replace my 98 Outback's (2.5l automatic) ECM with an ECM from a 97 5speed Outback?? Is there any compatibility issues here, or am I good to go?

I think you mean ECU. Not sure if the ECUs are the same, but on wiring diagrams they show both the manual and auto wiring. I know that the wiring harness' are different, but the connector is the same. The best way is to compare part numbers as stated in another reply. If there are ECU just for manual equiped cars and ECU for only automatic equiped cars, then it is unlikely that they are switchable.

ECM is commonly used as well "M" for Module.

 

i would bet they are interchangeable. XT6 ECU's swap between FWD, AWD, Automatic and 5 speed no problem. I do not know for sure, but i would bet the same is true of similar EJ models.

 

in the older generation EA82's there are many different part numbers for turbo, non turbo and such. There are a few differences across model change years and MPFI, SPFI, etc and such but many of the ECU's are interchangeable.

 

it really comes down to the wiring harness and i would guess that it is the same. I don't recall any major changes from 1997 - 1998. motor swaps are fine from 97-98 so i'd bet ECU's are as well.