I ran my 97 EJ25 Outback on a 97 Impreza 2.2 ECU, and got most of the same codes you're getting. The Impreza had different vacuum line routing and some differences by the fuel tank, things I couldn't overcome. I would have liked to continue running the Impreza ECU (the eBay listing I got it from shows a 3W on the box), because the throttle response and power was better, but with all those codes I wouldn't be able to pass yearly emissions, since Texas doesn't dyno them, just plugs into the OBD2 port. I was trying to avoid having to install EGR on the phase II heads I was running, but wound up with even more codes