Hey I just installed a PW tmic for my MY00 WRX. I get a whistle/whine noise aswell when boost hits or just before.

We re-used my gasket for whatever is on the front right side of the tmic (when looking from the front of the car, i guess its the bov exit or whatever?) I though if the gasket was leaking it wouldn't be all that loud but it's quite hear able from inside the car. I'm going to buy a new gasket from subaru early this week anyway. How, or why, could my bov be sticky like yours jedi luke?

air leak through gasket. spray some water and see it bubble.

i'll try this tomorrow

Got my mechanic to check the intercooler for any leaks, and yes, the leak was coming from the BOV gasket which was as expected after seeing a lot of people with the same problem.

I've installed the new OEM gasket and the leak has gone