Wastegate?

[IHateHacks]

"causing the exhaust to come out somewhere else, and making no boost"

The only thing causing exhaust to come out "somewhere else" and not make boost is an exhaust leak BEFORE the turbo. Would have NOTHING to do with the cat. Plugged cats don't cause exhaust leaks.

Let's review what we know (or what you said). You said you felt and heard an exhaust leak near the turbo, correct? Start there first before you go ripping apart the rest of the exhaust.

Wow that sucks about what that guy did to that exhaust. Did he weld the cat-back onto the cat also? If the cat back is still bolted to the cat (like it should be from the factory) then I would buy a test pipe and aftermarket downpipe. The dealer will rob you blind for a stock cat and downpipe. Would probably run you $700 if not more. If the cat back is welded to the cat then guess you have alot of work to do, buying flanges, cutting, welding, finding gaskets that fit. So much for a direct bolt on exhaust for your car.