Under the steering column on the 1990 Legacy I've slowly been stripping of parts, there is a gold box I thought at first was the ECU, until I realized the ECU was to the left of it. This box has three black plugs going into it and the letters "EF" printed on the side. What is it? And do I need it for the EJ-EA swap I'm trying to put together?

auto transmission control unit (TCU). unless you're re-using the auto trans, you won't need it.

Thanks - thats sorta what I thought, but the EF made me think perhaps there was somd distinction between the ECU and the MPFI controller and perhaps this was it.