WARNING: This page is about a different car, the 2016 Dodge Durango. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Locating Knock Sensor
Courtesy of CHRYSLER GROUP, LLC
The 5.7L engine uses two knock sensors (1) and are bolted to each side of the cylinder block (outside) under each exhaust manifold (3).