Overboost code and excess exhaust smoke

So a few weeks ago I was just driving to work at about 55moh with cruise on when it went in to limp mode, checked the codes it was p0234 overboost, I cleared the code and it hasn't came back but I notice a lot more black smoke and kind of a hesitantion to build boost. She's fully deleted with a race pipe and I just did a S3 intercooler to fix the boost leaks from the factory oring seals which were leaking quite a bit of oil, and I have a stage2 Malone tune, she's a 2013 beetle with 106, what I'm asking is could this be the turbo? I found a bunch of soot by the vnt shaft as well. Thank you

From ross-tech:
Possible Causes

• Hoses incorrectly connected, disconnected, blocked or leaking
• Boost Pressure Control Valve (N75) faulty
• Boost Pressure Sensor (G31) faulty
• Turbo Charger stuck/faulty

So yes, could be turbo

I've checked the lines they are good, and I tested the n75 and the g31 with vcds they both functioned normally, I went ahead and ordered a cr170 turbo last night, seemed like a good idea to upgrade for not much more then a stock turbo