I've been asked in a pm to make a thread of how and where to do an Upper Cylinder Clean with the Subaru product.
I am collecting photos at work as I work on various libertys, so hold tight for them in the next week or so. If you want help for a specific car, then post up an engine bay pic and I'll help you out. So far I have Gen4 N/A photos and Gen3 N/A photos.
The Subaru product does have instructions on the can, which are very simple to follow, but it can be time consuming. The way workshops do it is simply rev the engine at abour 2,500rpm and spray the cleaner into the intake.
On non turbos (H4 and H6) undo the intake piping hoseclamp on the throttle body, use a large flat blade screw driver to make a gap between the piping and the throttle body and put the end of the Upper Cylinder Cleaners spray hose in and spray the contents of the can into the throttle body with the engine revving. When the can is empty run the engine for another 1-2minutes to burn off the excess in the intake. When spraying you will notice a big cloud of smoke from your exhaust, it is normally a white smoke, this is normal as its cleaning the carbon out the engine.
For turbo models there are 2 methods: Again, rev the engine to about 2,500rpm.
Method 1: Disconnect the vaccuum hose on the BOV and slowly spray the contents of the can into the vaccuum line.
Method 2: Undo the hose clamp on the throttle body and use a large flat blade screw driver to make a gap. Spray the can into the intake with the engine revving.
Method 2 is suited to B4s and older turbos as Gen4 turbos have the intake piping under the intercooler and manifold.