Firstly, congrats on owning a P337!
I hope you got some consideration from the seller because it won't hold pressurization. I hope its just a dump valve, but I doubt it. Keep us informed.
The rpm situation on the front motor indicates one of three things:
1. Weak turbo
2. Weak/misadjusted wastegate
3. Intake leak
I'm sure there are other possibilities, but chances are good you'll find your issue in one of the above.
Enjoy your new airplane and don't forget: PICTURES OR IT NEVER HAPPENED!!!
