pretty sure it is not that as my blocking plate is only 1mm thick and fits inside the gasket .
- my leak happened after some high boost runs so it was like something failed rather than was there all along .

Did you try idling while spraying areas with contact cleaner?

When you hit the leak it affects the idle, and with those little red spouts you can get right to remote areas.

After that I'm kind of out of ideas, though I have seen the same technique using a propane hose....

yes.

The propane torch idea works. The idle will go way rich and you can find leaks pretty easily (easier than soapy water in my experience).

I took of the UIM on the weekend and the first plastic to plastic junction the seal didn't look like it was doing a good job. after putting it back together it hasn't stopped the squealing noise.

I'll try the contact cleaner idea thanks for the tips.

i myself had a boost leak coming from t he secondary shutter valve. I tried to overtorque it down to shut it up and eventually broke the bolt. Then i tore everything down and i found out the gasket around it was damaged got that now im waiting on the bolt.