Knock Sensor 1 -G61-, Removing And Installing: Notes
WARNING: This page is about a different car, the 2020 Audi A3, 2019 Audi A3, and 2018 Audi A3. However, it is still accessible from the selected car via links, so may be relevant.
Component location: under the intake manifold behind the Engine Temperature Control Actuator -N493-.