WARNING: This page is about a different car, the 2018 Audi S6, 2017 Audi S6, and 2016 Audi S6. However, it is still accessible from the selected car via links, so may be relevant.
Courtesy of AUDI OF AMERICA, LLC
-- Disconnect the connector -2-.
-- Remove the bolts -1-, and remove the Charge Air Pressure Sensor -G31-.