So I removed the Alternator and air pump. This helps access wise. I then removed the right intake manifold. I saw that the check valve input (vacuum side) was not connected to anything. (more on that). I removed all of the SAI components and hooked up everything on the bench and vacuum tested with the HF brake bleeder pump. Everything held up. I blew through the shut-off valve and it was closed tight. I applied 12V to the change-over valve with my bench supply and the change-over valve opened with a resounding clunk, and air moved freely. Initially I couldn't find where vacuum line to the check valve was but found it. I think I might have disturbed it when I cleaned the throttle body a month ago, and it slipped off.
Boxster Base
Threaded Mode
