EMU Black Sensor Problem after install Soundsystem

Hi Community
I have a problem with a sensor after install classic soundsystem in a golf 2
Before car runs perfect
I wiring the amp from the battery directly to the amp a 800w amp and 1000w subwoofer
All works fine when car is not running
But car is running and make music very loud
Engine stop and I have in the error code list
CLT,IAT,DBW,FPR,OILP
After make music system out car works fine
But sometimes fuelsave and I have the error code fpr now
I use a Bosch 0261230482 cpts sensor
All 3 pumps working fine
I will check next days with a new sensor
Anybody have a idea maybe I kill the sensor or ecu with this ?
Thanks for help
Greetings Tristan

What’s the total system voltage when the music is loud? Is the amp ground going direct to battery as well?

Hi
I never measure the voltage when music system was loud or check in ecu software and no log
I connected the body ground in the trunk and the plus cable directly to the battery