I have a code P0304 & P0325. The knock sensor and cylinder 4 misfire. How do I repair the problem

Question edited for clarity and the typos - Nissian, cyclinder, vam, and PO 304 is P-zero not P-letter Oh..
Question moved to model category

What makes you think it is the Crankshaft Sensor? This is a simple misfire on Cylinder 4. Check plug, leads and coil. Run some Injector cleaner.

The P0304 code stands for "Cylinder 4 Misfire Detected", which means your vehicle's cylinder 4 has misfired enough times for your powertrain control module (PCM) to notice. A worn spark plug, a faulty fuel injector, and a leaking valve are some possible causes of the P0304 code.
Jul 28, 2023

P0304 Code: Cylinder 4 Misfire Detected - CarParts.com

https://www.justanswer.com/nissan/58ol6-2004-nissan-quest-5spd-where-crankshaft-sensor-located-diy.html

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P0300 Random/Multiple Cylinder Misfire Detected P0301 Cylinder 1 Misfire Detected P0302 Cylinder 2 Misfire Detected P0303 Cylinder 3 Misfire Detected P0304 Cylinder 4 Misfire Detected P0305 Cylinder 5 Misfire Detected P0306 Cylinder 6 Misfire Detected P0307 Cylinder 7 Misfire Detected P0308 Cylinder 8 Misfire Detected P0309 Cylinder 9 Misfire Detected P0310 Cylinder 10 Misfire Detected P0311 Cylinder 11 Misfire Detected P0312 Cylinder 12 Misfire Detected P0313 Misfire Detected with Low Fuel P0314 Single Cylinder Misfire (Cylinder not Specified) P0315 Crankshaft Position System Variation Not Learned P0316 Misfire Detected On Startup (First 1000 Revolutions)

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p0171 = fuel system too lean, this means vacuum leak or faulty oxygen sensor

p0303 = cylinder 3 misfire

p0325 = knock sensor malfunction.

p0303 and p0325 - i can see these working together, if a cylinder misfires, it will cause the knock sensor to trip. I would lean towards the coil and or ignition module, along with a faulty oxygen sensor.

P0325 knock sensor 1 circuit malfunction bank 1 or 1 sensor, the knock sensor should be check/replaced. You can buy Haynes Repair Manuals at Pepboys that will walk you throught the process step by step.
P0303 is a cylinder misfire in cylinder 3 which may mean it could either be the spark plug, coil or the injector.

P0301 Cylinder No. 1 Misfire Detected
P0302 Cylinder No. 2 Misfire Detected
P0303 Cylinder No. 3 Misfire Detected
P0304 Cylinder No. 4 Misfire Detected
P0305 Cylinder No. 5 Misfire Detected
P0306 Cylinder No. 6 Misfire Detected
P1346 Variable Valve Timing (VVT) Circuit Range/Performance Fault
P1349 Variable Valve Timing (VVT) System Malfunction
P0330 Knock Sensor
P0446 EVAP Vent Control Fault
P0430 Catalyst System

Stop driving immediately.....

You defiantly skipped on your timing........

Generic OBD II Diagnostic Trouble Codes

DTC CODES P0300 to P0399

P0300....Random/Multiple Cylinder Misfire Detected

P0301....Cylinder 1 Misfire Detected

P0302....Cylinder 2 Misfire Detected

P0303....Cylinder 3 Misfire Detected

P0304....Cylinder 4 Misfire Detected

P0305....Cylinder 5 Misfire Detected

P0306....Cylinder 6 Misfire Detected

P0307....Cylinder 7 Misfire Detected

P0308....Cylinder 8 Misfire Detected

P0309....Cylinder 9 Misfire Detected

P0310....Cylinder 10....Misfire Detected

P0311....Cylinder 11 Misfire Detected

P0312....Cylinder 12 Misfire Detected

P0313....Misfire Detected with Low Fuel

P0314....Single Cylinder Misfire (Cylinder not Specified)

P0320....Ignition/Distributor Engine Speed Input Circuit

P0321....Ignition/Distributor Engine Speed Input Circuit Range/Performance

P0322....Ignition/Distributor Engine Speed Input Circuit No Signal

P0323....Ignition/Distributor Engine Speed Input Circuit Intermittent

P0324....Knock Control System Error

P0325....Knock Sensor 1 Circuit (Bank 1 or Single Sensor)

P0326....Knock Sensor 1 Circuit Range/Performance (Bank 1 or Single Sensor)

P0327....Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)

P0328....Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)

P0329....Knock Sensor 1 Circuit Input Intermittent (Bank 1 or Single Sensor)

P0330....Knock Sensor 2 Circuit (Bank 2)

P0331....Knock Sensor 2 Circuit Range/Performance (Bank 2)

P0332....Knock Sensor 2 Circuit Low Input (Bank 2)

P0333....Knock Sensor 2 Circuit High Input (Bank 2)

P0334....Knock Sensor 2 Circuit Input Intermittent (Bank 2)

P0335....Crankshaft Position Sensor A Circuit

P0336....Crankshaft Position Sensor A Circuit Range/Performance

P0337....Crankshaft Position Sensor A Circuit Low Input

P0338....Crankshaft Position Sensor A Circuit High Input

P0339....Crankshaft Position Sensor A Circuit Intermittent

P0340....Camshaft Position Sensor 'A' Circuit (Bank 1 or Single Sensor)

P0341 Camshaft Position Sensor 'A' Circuit Range/Performance (Bank 1 or Single Sensor)

P0342....Camshaft Position Sensor 'A' Circuit Low Input (Bank 1 or Single Sensor)

P0343....Camshaft Position Sensor 'A' Circuit High Input (Bank 1 or Single Sensor)

P0344....Camshaft Position Sensor 'A' Circuit Intermittent (Bank 1 or Single Sensor)

P0345....Camshaft Position Sensor 'A' Circuit (Bank 2)

P0346....Camshaft Position Sensor 'A' Circuit Range/Performance (Bank 2)

P0347....Camshaft Position Sensor 'A' Circuit Low Input (Bank 2)

P0348....Camshaft Position Sensor 'A' Circuit High Input (Bank 2)

P0349....Camshaft Position Sensor 'A' Circuit Intermittent (Bank 2)

P0350....Ignition Coil Primary/Secondary Circuit

p0304 misfire on cylinder #4
p0325 knock sensor circuit

Could be a bad wire, plug, or coil pack on cylinder #4 (or bad distributor connection).

Knock sensor indicates a knock coming from the engine, perhaps from cylinder #4.

This may lead to a diagnosis if you change parts related to cylinder #4.

Good luck.

P0325 is a knock sensor. the knock sensor will not set the ses ligth

Here you go:
P0305 Cylinder 5 Misfire Detected
P0325 Knock Sensor 1 Circuit Malfunction (Bank 1 or Single Sensor)

The 305 is most likely caused by a faulty knock sensor.(325)

codes 03-40 are misfires on cylinders 3 & 4 and 325 is ur knock sensor if u had bad gas/water in tank or need tune up and those 2 cylinders misfired could set off code for knock sensor or visa versa as to abs light sheck sensor wires for connection and or damage none observed have rescanned and find out if sensor or unit if sensor scan code will tell u which one ur directional usually blinks faster on the side with the bulb out