Boost controller issue or wastegate?

[asshanson]

Maybe your MBC is broken. Hook the wastegate directly to the boost source off the BOV and see how many psi it makes. Make sure that line isn't clogged or kinked.

If the boost gauge line was kinked it would show zero boost, but if the line to the wastegate wasn't working right it wouldn't open at all which is what it sounds like. Or you have a bad wastegate that doesn't work. You could probably take it off the turbo and have it pressure tested to make sure the arm moves at a certain psi.