06 Evo IX. 11k miles. Boost leak tested to 24psi. only mod is turbo back exhaust.
Something seems to open up around 5k. It doesn't matter what gear. I tried a manual boost controller, a different BOV. Removed and reinstall all hoses and pipes. Boost leak tested thru the turbo with a MAF delete intake pipe. The only one I have left to test is the turbo but I can't convince myself that its the turbo since the issue is always at around 5k rpm doesn't matter what gear. I can hear something opening like the BOV leaking. Boost drops 5psi when it happens.
Any help or ideas what else to check.
Stock ecu(was flashed on dyno) but now back to stock.

 

You need to search for Bat-Talon, and you will find the answer immediately.

PS. Intake Snorkel

 

Thanks alot.
I mean it.

 

I agree with Warrtalon. It sounds like Intake Snorkel to me.

 

Sounds like he's good to go. Easiest fix ever to what seems like the worst problem ever. Relief is abundant. Merry Xmas.