Need your HELP!

I got the P0300 code and the car went into limp mode.
I found marten bites in two rubber lines. I fixed them and erase the error code.
Now the car overboost but without power.
The car had a chiptuning, FIMC, AEM Intake. After chiptuning the boost was by 17 PSI.
Now the boost goes up to 20 PSI but without the power I had before.
I changed - sparks, Coil plugs, wastegate solenoid valve, can´t find any leaks and no error codes shows up.
Please anyone has an idea what I can looking for or had the same Problem?
I´m from Germany (sorry for my english)