ESP Rattling: Causes and Solutions

Hello everyone!

I just replaced the timing belt and everything that goes with it. After that, I, of course, adjusted the injection timing. While doing that, I noticed the following:
In the basic settings, everything runs quietly and smoothly. However, when I exit the basic settings, my ESP starts making a very high-frequency rattling noise! It's really noticeable. Is this normal? Can you hear the fuel injector working, or is my ESP failing?
Besides the ESP issue, there are no other signs of a malfunction. The injection timing and fuel quantity are working correctly, the pump is leak-free, and there's no noticeable shaking or vibration.