Ok, first off:
My car is a '97 A4 1.8t. The turbo has been upgraded to a Ko4 with no other mods besides a TT Diverter Valve.

Ok, so a while back I had been pushing about 18-19 psi peak and it would slowly drop down to maybe 10 (maybe not even this low, it's been a while) by the time it was ready to shift. I got a HUGE boost leak out of my turbo outlet pipe, unfortunately I could not find a single place to get a replacement so I ended up using 3 rolls of silicone tape to repair it. It seemed to work pretty good, no more air release noise under load, nice a quiet with just the little tiny whistle of the turbo, but it went down to about 16 ish pounds on gears 3-5 which wasnt really an issue. Right now though, the "airy" noise is back, but I cant find the leak anywhere. I checked the outlet pipe, the inlet pipe, the pipe from the intercooler to the intake manifold. the vacuum lines from the intake manifold, and tightened my connections for the boost guage. Still couldn't find a hole or anything.

Right now I am getting about 14 psi of boost peak, but if I'm going lets say.. 30, in 4th and I floor it, it spikes back and forth rapidly between 10-14 pounds. Also, I heard about unplugging your MAF, but when i unplugged it i peaked at exactly 5psi no more no less and no spikes. the same happened when i disconnected my n75. I sprung no CELs though.

So my questions are this:
1. Why am I (or was I) peaking at such a high amount over stock.
2. Why is my boost spiking at low rpms at WOT
3. Is there anything I can do to troubleshoot this quickly? (I have no garage and the wind chill here is wicked)

I will try to post a video of the boost spikes
'97 Audi A4 Boost Spikes, help? - YouTube