I am trying to figure out what ecu will work in my 99 impreza. I have read 99 to 01 will work, but I have also read 99 only. My 99 ecu says b1 on it and I can get an 01 ecu but it has b2 on it and they have different part numbers. The 99 is 22611ae511 and the 01 is 22611ae523. Both are from 2.2 with 5 speed.

 

Anyone now if that would work.

Why do you believe you need a replacement? This is not common.

 

GD

It's explained in my other post (99 impreza power loss).

 

I know its very uncommon but i have to try.

 

So, any idea on the ecu fitment

It's not going to be the ECU. Get back to basics, there's a lot that hasnt been tried. You already scrapped a good motor by just throwing darts at the wall on this.

 

Plugs, wires, coil, fuel pump, pressure regulator, injectors, map, knock sensor, TPS, o2s, blocked cats, IACV, EGR, fuel filter (and more that I'm likely forgetting)

 

If you are not sure of these things, you're wasting time and $$$ by thinking the ECU will solve anything. (As you already learned having needlessly swapped the motor and scrapped the one that never needed replacement in the first place)

 

This sounds harsh but is not intended to be. Just a good natured kick in the pants to stop chasing rabbit holes and start looking in the right places. The shotgun approach to diagnosing an issue is a black hole for time and $$$. If you cant diagnose it yourself, pay someone who knows subaru specifics to do it for you. (Not the guy who told you to swap your motor)  You will come out ahead in the long run.

As said rarely do ECUs fail. But they are cheap and easy.

 

Car-part.com and buy the cheapest one in the US.

 

EJ25s work as well. Use one from a manual transmission. But you can't use a 99 Legacy EJ25 or Outback as those are Phase I. So for EJ25s use a 99 Forester, or any 2000-2001 EJ25.

And again I think you have to use a manual trans.

 

The one you mentioned should work. There are two different sets of cam/crank triggers in 99+ vehicles and I *think* those triggers vary based on auto and manual.

 

thoae two different triggers are the only variation for 99-2001s you need to worry about.

 

And actually I'm older Subarus they could actually run automatics or manuals, they can *tell* what transmission it is by the pins. Install a manual ECU into an automatic no big deal.

 

But I'm not sure you can do that with Phase II stuff.

1999 is maf, 2000-1 is map. Not going to work well. Try something else first

Edited August 5, 20178 yr by matt167

I replaced literally everything except the cat when I did the motor swap. I used a complete different motor and intake, so no sensors were reused as well as plugs and wires. Fuel pump and filter were replaced with new ones and the car was in a reputable shop that tested the cat. I am down to either a wire problem in the dash or ecu. Unless I am missing something else.

 

I did try an ecu from an 01 5 speed impreza and it wouldn't even start. Put the original ecu back in and it fired right up so I am thinking the ecu is 99 impreza only. Which is what I found on a couple sites.

o2 sensors replaced?

It's not the ECU. There are more sensors than just what's on the engine. There are neutral, clutch, and brake switches, map sensor and map sensor switching solenoid. Problems with such as you describe can be due to intermittent problems with this equipment and may not throw a code. You need to get an SSM cable, and datalog all the sensors inputs with EVOScan. I've seen this before and IIRC it was a problem with the MAP and/or pressure sensor switching solenoid. Either incorrectly plumbed or intermittently bad.

 

GD

According to the mechanic (who I know and trust) the knock sensor was picking something up and regarding the timing. He was able to see it happen on his scan tool. Everything else tested fine. He suggested replacing the knock sensor to make sure it wasn't bad, but he was pretty sure it was picking up a noise from within. I did replace it and it still did it.

 

Would any of the mentioned sensors cause the knock sensor to do that.

MAF/MAP - they're not on the engine - did you replace all those?

 

Will these engines run by disconnecting the knock sensor? If so you could disconnect it or jump it with an appropriate resistor as a temporary test of the sensor and circuit.

 

I'd still disconnect the fuel line when it's not running to make sure fuel is flowing. You can install engines and pumps all day long but if nothing is getting through they're all useless.

inspect all your PCV and IAC lines and the intake plenum.

 

Also, make sure the air cleaner above the throttle body is latched correctly.  It's downstream of the MAF, and if the tabs at the bottom don't engage all the way it won't seal and you'll have an unmetered air leak.