Greetings i need help my polo tdi 1.6 loose power when i turn key off and on while in a motion the power came up again and i've changed many parts but there's no help still

Do a fault scan via VCDS or similar and then take it from there.

Changing parts without knowing what fault codes there are is a simple waste of money and time.

I already scanned it many time and i go to Bosch service they scanned it and the told me to change timing ket and water pump i chaged them but the problem still the same... i change almost all sensor but still no help!

What are the fault codes?

P261B00