97 Mercury Villager - Codes P0325 & P0306

My villager just hit 183k miles on it 2 days ago. The same day, it started sputtering somewhat and the check engine light started blinking on and off and then just stayed on. Yesterday my neighbor hooked his tester up to it and it read 4 problems but it was actually reading P0325 (knock sensor 1, circuit malfunction, Bank 1 or 1 sensor) twice and P0306 twice. I drove the car this morning and it seemed fine, no problems noticed. But this afternoon when I drove it to take my daughter to work, I noticed a minor skip or sputter but nothing bad, but then my oil light started blinking and I started hearing some clicking. My husband had just checked the oil last night and it was fine. I stopped and bought a quart to put in it and drove it just a few miles and it started again. It's now sitting in the driveway and I won't drive it again until it's fixed. Would these 2 codes be related to each other causing one or the other? And from reading about knock sensors, it seems that the engine can run hotter than you know? Could this be the reason of my oil situation? Also, the car really acted up if I turned my a/c on. Even though it's a Mercury, it has a Nissan engine in it.

P0306 Cylinder 6 Misfire Detected
P0325 Knock Sensor 1 Circuit Malfunction (Bank 1 or Single Sensor)

If it is a single cylinder, #6, causing the problem then you're lucky because this is easier to figure out the cause.

If one cylinder, #6, is only affected ( code P0306). Then look at changing ( examine them ):
1) spark plugs
2) ignition wires
3) distributor cap & rotor
4) replace ( or check ) cylinder 6 fuel injector
* check engine after each one is done

If the whole engine is affected then it'll be tougher to figure out. And many more things to check & change.

Driving a vehicle with a knock is not good because you'll damage the engine.

Work on & fix P0306 first & P0325 may go away.

the P0325 is going to probably stay with you until you replace it. Nissan knock sensors on the VG/VQ engines go out normally. However, check the injector and plug/wire on that cylinder, I'd bet a paycheck on an injector.