My BAII XR8 was on the dyno today at Blue Power we after a less then deirable first run we started hunting for a problem. On closer inspection we found a large build up off carbon and grime in the throttlebody and inside the plenum. We cleaned up the throttlebody and as much of the plenum as we could with a rag and some throttlebody cleaner and power improved greatly, however there is still more grime in the plenum and I would like to get it all out. Has anyone removed their plenum before and is there anything I should know about before I attempt to remove it. I have a good mechanical understanding and am handy with cars I just want to make sure theres nothing to tricky. Any help wouold be great

Try this before your tear it apart.
Go to Subaru spare parts and ask for a couple of cans of upper cylinder cleaner. (Silver Cans)
Follow the instructions on the back of the can and see how it goes.
This may do the job for your.
I have had good results using this stuff on my vehicles.
Expect to pay around 14 bucks a can.
Beats getting that manifold off any day.
Regards

One of my best mates works at subaru, i'll have to ask him about it. I'd still like to take it off and get all the grime out. As it was evident that the car had potential to make more power then it did it this is the most likely cause

Give it a try its pretty good stuff.
I had to removed a manifold on my pajero to do the plugs on it and upon inspection it was clean after using this stuff.
Your supposed to apply it via a vacume hose but if you want a more thorough job without removing the manifold just remove or open or remove the throttle body and give it a good squirt that way.
Initial start up may be difficult doing it this way but keep the revs up and it will clear the remaining stuff out.

The manifold is not too hard to take off. You do need special TORX sockets & the gaskets if needed are bloody deer. Regards TPVM.