Still getting MAF codes after Replacing MAF sensor

I’d find a Subaru forum, they have their quirks and you might find folks that have done this swap.

You could check with an auto recycler (AKA junk yard) on locating an ECU/ECM for a 2.0 and see if that corrects the problem.
As far as a shop that does tunes, kind of a dice roll, some shops may be great, some might send you down a rabbit hole.

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Gotcha that all makes sense. From what the seller told me he swapped the engine after the previous one blew a bearing and he turned it into a project, but got busy with like 6 other cars and just decided to sell it after he got it running. It’s in great condition for the situation and I’m excited to learn what the next step is.

I’m most likely gonna try to switch to. 2.0 ecu. I’m wondering what kind of problems I might run into though. I’m sure it’s not as easy as just plug and play. Is there any common things I should expect to deal with once I get an ecu like compatibility with different parts or anything else? Like how do I know what ecu works with the ej20 engine as well as the car as a whole?

Any particular forums better than others? Kinda thought this was one lol

That’s what I was thinking. Any chance it won’t work with other parts of the car though?

What I would suggest is to make double sure there are no vacuum or air leaks both above and below the throttle plate. A leak anywhere can cause perceived MAF issues. Loose clamp, cracked vacuum line, fuel injector seal leak, PCV hose, etc, etc.

I check for leaks with a vacuum gauge, visual, and a smoke detector although I realize the smoke thing might be a pricey for a DIYer. I actually made my own smoke detector years ago after seeing the price on a MAC unit. Ouch. Well north of 1100 dollars vs 75 made the decision easy.

I don’t know the specific forum that would be best. You’re asking a pretty specific question about a modded car, for those a specialized forum might have more members familiar with your question.

Okay, now if you don’ want to go to all stock up front, you first could follow the advice others have given to match all of the critical parts to your current engine - engine control computers and their programming, sensors, manifolds (if they differ), etc., and check that these parts are functioning properly. Subaruoutback.org and similar also might have more specific info.

Yes, there is definitely a chance of problems. Your odds can be improved by obtaining the ECU from a dealership (who will know the questions to ask), after that best chances are an ECU ripped from a junkyard Subie, same model year, same model, same engine & powertrain configuration.

I understand that “anything can be fixed” but within a budget, a 1994 Subaru 2.0 engine with 1996 2.5 ECU, with modifications?

My best advice would be to locate a cheap 1994 ECU to get it runnning and then stripping off any any “modifications” that present a problem…
Basic steps would then be cleaning out the throttle body, checking electricle system, fuel pumps, fuel filters other filters and brake systems to get everyything back to original specifications.

Afterwards change the ECU, NOS, supercharge it, bore and stroke it it’s all up to you but you’ll know what you’re getting ino.

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