frustration!

Ok, So my car is a 97 A4 Quattro 1.8t.

The basics of this problem are:
1. Hissing noise (I think is a boost leak.... somewhere..)
2. Boost is peaking at 4-7psi (normally peaks at 15-19)
3. Diaphragm on the stock DV went bad. (you could blow/suck through one of the big openings and the top nipple.
4. Just replaced the DV with a 06A 710N from ECSTuning this morning. (boost levels went from about 3 psi peak to 4-7 psi peak. Hissing noise under boost also got quieter.)
5. Before the DV got replaced the car would stutter REALLY bad from 2-4 thousand rpm. So far after it's been replaced the stutter seems gone.
6. I found a vacuum leak on the old braded tubing I spliced the boost gauge to. Replaced the tubing temporarily.

That's just about it. the car is pretty ridiculously slow. (at least the stutter is gone - under stutter it would actually almost stall out the car and lose speed.

Any kind of help would be GREATLY appreciated, troubleshooting this kind of stuff is such a pain.

Also: when the car first started the hissing noise my boost slowly dropped, and dropped more and more every day since then. If anyone would like to text or call me to help out with the issue that would be amazing, you can just PM me a way to contact you. Thank you so much.

 

Update: Took off the hose from the pressure outlet of the turbo to the intercooler/diverter valve and had a HUGE tear. Silicone taped it and its holding boost to 10 psi until the tape start letting air pass and squeak through. will hold up to 15 pounds right now though.