any misfire, engine shaking, bad gas, could cause a knock. but your p0326 is circuit/voltage related.
still not sure on your year/model. if you have 02-03 qr25, this is a common problem, many people just relocate the knock sensor, but its possible you may need to reground it, or replace it.
this knock sensor is not directly affected by your p0420 cat code, if fact, if you have a p0420 your ecu should richen the afr causing leaving a knock less likely to occur. if you have all these voltage related codes, i would question your battery, battery terminal tightness, ground contact, voltage motor on&off, just in case youre getting these codes from lack of voltage to random sensors.