Knock sensor code, service engine light

Given the mileage, it's more likely there's a rattling in the engine that is being detected as a knock. A sloppy timing chain is a good suspect. The clue is while driving with a scanner connected to view live data, you'll see ignition timing continually being retarded in an attempt at stopping that knock.

It's also important to know the exact fault code number. That will tell whether there's an electrical problem with the circuit, or the sensors are working properly but responding to something.