Replaced the turbo and now it won't boost

Hey everyone, I recently bought an '88 LeBaron Turbo. After a few weeks of owning it, the Oxygen Sensor went out and the car went into limp mode. It was the original and had 145,000 miles on it. No one could get it out without cutting it, so I figured, at nearly the same cost, I would just switch out the whole turbo for a new one. (It was $250 - $300 shop work to cut out and rethread the oxygen sensor and $325 to swap out the whole turbo and downpipe for a new one).

So, either way, that's what I did and now that I have it back it no longer goes into limp mode but the turbo feels like it just won't build any boost. I used to have a Dodge Spirit with the non-turbo 2.2 and it feels just like that. If I remember right, the LeBaron's boost is computer controlled. Could something be limiting it to 0 lbs of boost?

Also, I ran a computer diagnostics on it and it threw a code of 12, battery recently disconnected, which makes sense since it was just worked on and they disconnected the battery.
What could be causing this? The old turbo boosted just fine.

Check your vacuum lines and routing. Sounds like the wastegate is stuck open on continuous vacuum.

I went through the vacuum diagrams step by step and it looks like everything is in order and in the right place. There were a few of the larger hoses that went into the air cleaner box that had some surface cracks in them, but nothing major. Is there anything electronic/computer controlled about the boost that I could check in the engine? I have an appointment with the shop and they're going to go through it and see what went wrong, but it's still not for another week and I wouldnt' mind fixing it myself before then if I can.
Also, I have a boost guage, which line can I tap into to get a turbo boost reading?
Thanks.