P0170 Audi - which bank 1 sensor is it

Question

Engine code P0170 indicates potential fault with Bank 1 sensor but there are 2 bank 1 sensors. How do you tell which it is.

Answer 1

if the oxygen sensor is bad its usually sensor 1 on bank 1. Sensor 1 is on the exhaust manifold (on the header) 

bank 1 sensor 1 is on the driver side, in the rear of the motor. 

See picture below