Originally Posted by SOLUTION
Here is a shot of the '05 manifold. On the floor to the left is the IAC and on the right, next to it, is the IAC from an '00. Circled in the picture is where the IAC mounts - it has one passage that leads to the pipe I drew an arrow to and the other leads to the penile looking thing to the left of the mounting location.
That looks more like the EGR port to me, particularly when you say that it looks sooty. I have two intakes sitting in my garage - an EJ25D and an EJ20G - and on both of those the IAC port is just a circular opening. Just took some pics now....
The EJ25D's EGR port looks like so...
Obviously not exactly the same as your '05 intake, but note the split port and also the port below where the EGR attaches (it's not penile on the EJ25D intake
, but it otherwise looks the same). You can kind of see in the picture on the bottom of the intake the same sort of passage snaking along the bottom towards the center of the intake.
Based on some PMs I've bounced back and forth with Jay Storm, there are some older Subies that had the IAC integrated into the throttle body. Perhaps with the throttle-by-wire the '05+ cars are able to control the idle with the throttle body?
'97 Legacy 2.5GT sedan