Started about 2 weeks ago after my boost gauge stopped working. Traced the vacuum line that popped off gauge works again but the whistle is still there but I can't seem to find any broken or leaking vacuum lines on the passenger side. Any ideas ?

 

Try a boost leak test.

 

Yep you have a leak. I had one like that one time and is was from a loose bolt for my old Greddy BOV on my 1g. They bolted down like the stockers just on a different bolt pattern. It worked loose and let boost out like a reed on the gasket.

 

I haven't noticed a boost leak I'll run through the system and tighten it all up hopefully that works

 

You most usually wont see a leak. Its like lookin at the sky to see air. A pressure test of about 5-10 psi higher then your set boost will tell you more then just a visual inspection. You should have a boost leak tester in your tool box of stuff when you own a Evo/DSM! Its the number one tool.

 

Yes I learned that lesson with my srt4