[DrVenture]

Beside the sound advice of finding a shop with a top notch diagnostician, I would suggest the following: All the codes that you posted have to do with the charging pressure sensor. I would suspect one of three things:

1. Faulty charge pressure sensor
2. An issue with the wiring/connectors to the charge pressure sensor (121002 Charging pressure sensor, electrical: Short circuit to earth. Intermittent).
3. Something affecting the charge pressure, like a leak (121202 pressure too low).

Since the car was worked on extensively, I would be very suspicious that a wire to the charge sensor is pinched or a connector is not plugged in securely. I would check that circuit using schematics to identify the wiring and connectors. And test/swap the charge pressure sensor. If no problem found, I would look for a leak from the turbos (charge pipe crack/damage?). Perhaps even a problem with the waste gate solenoid not functioning properly.