2004 ram 1500, 3.7L 6 cylinder. P0300 & P0304 codes. Changed all plugs, coil on cylinder 4, injector on cylinder 4, desludged engine, sea foam to gas tank, and it still has a miss at idle and above

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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p0171 is fuel injection system too lean - bank 1
possible causes
- Intake air leaks - Faulty front heated oxygen sensor - Ignition misfiring - Faulty fuel injectors - Exhaust gas leaks - Incorrect fuel pressure - Lack of fuel - Faulty Mass Air Flow (MAF) sensor - Incorrect Positive Crankcase Ventilation (PCV) hose connection
p0304 is cylinder 4 misfire detected.
possible causes
Faulty spark plug 4 - Clogged or faulty fuel injector 4 - Faulty ignition coil 4 - Fuel injector 4 harness is open or shorted - Fuel injector 4 circuit poor electrical connection - Ignition coil 4 harness is open or shorted - Ignition coil 4 circuit poor electrical connection - Insufficient cylinder 4 compression - Incorrect fuel pressure - Intake air leak
p0305 is same as above but cylinder 5.
p0306 is same as above but cylinder 6.
p0300 is random misfire detected
possible cause
Faulty spark plug (s) - Faulty ignition coil (s) - Clogged or faulty fuel injector (s) - Intake air leak - Fuel injectors harness is open or shorted - Fuel Injectors circuit poor electrical connection - Ignition coils harness is open or shorted - Ignition coils circuit poor electrical connection - Insufficient cylinders compression - Incorrect fuel pressure

P0300: Random Cylinder Misfire Condition
http://www.autocodes.com/p0300_toyota.html

P0301: Cylinder 1 Misfire Detected
http://www.autocodes.com/p0301_toyota.html

P0304: Cylinder 4 Misfire Detected
http://www.autocodes.com/p0304_volkswagen.html

P0300 is random misfires. Meaning more than one cylinder was misfiring. Year make model and engine size helps. On 4 cylinders 1 and 4 fire at the same time, this would be an ignition module. On a lot of models.

miss fire check coils or plugs

Did you clear the codes after playing with the wires and injectors ?
Have you checked for injector pulse on all 6 injectors ?

Engine missfire Cylinder #4

P0300 at P0304 Diagnostic Code - Random Misfire
Technical Description
Random/Multiple Cylinder Misfire Detected

What does that mean?
Basically this means that the the car's computer has detected that not all of the engine's cylinders are firing properly.

A P0300 diagnostic code indicates a random or multiple misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0302 code, for example, would tell you cylinder number two is misfiring. Unfortunately, a P0300 doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why.

Symptoms may include:
* the engine may be harder to start
* the engine may stumble / stumble, and/or hesitate
* other symptoms may also be present

Causes
A code P0300 may mean that one or more of the following has happened:
* Faulty spark plugs or wires
* Faulty coil (pack)
* Faulty oxygen sensor(s)
* Faulty fuel injector(s)
* Burned exhaust valve
* Faulty catalytic converter(s)
* Stuck/blocked EGR valve / passages
* Faulty camshaft position sensor
* Defective computer

Possible Solutions
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.

Hope help with this (remember comment and rated this).

have you changed out plugs or wires recently? if not its possible that these are original and that you need to replace them, now just take a quick look at the coil tower post for the number four cylinder, sometimes the post and the inside of the plug wires will be dirty or corroded and also re-seat the plug wire on to the #4 plug it might just have a bad or dirty connection. If this is a fuel injection system then go down to Autozone purchase a can of Sea foam ($10) just bot mine yesterday.. and fill up gas tank half way, then put in can of Sea foam drive it around for about 20 minutes and get on it ever so often, drive safe though please.. you might get lucky and it might just be a clogged injector. Can i get a very helpful thanks!

CODE 27 - Injector Control Circuit, output driver does not respond properly to the control signal

Code 27 MIL light options: OBDII
P0201 - Injector #1 Control Circuit
P0202 - Injector #2 Control Circuit
P0203 - Injector #3 Control Circuit
P0204 - Injector #4 Control Circuit
P0205 - Injector #5 Control Circuit
P0206 - Injector #6 Control Circuit

CODE 43 - Cylinder Misfire, or Ignition Primary Circuit

CODE $# MIL options: OBDII
P0300 - Multiple Cylinder Misfire
P0301 - Cylinder #1 Misfire
P0302 - Cylinder #2 Misfire
P0303 - Cylinder #3 Misfire
P0304 - Cylinder #4 Misfire
P0305 - Cylinder #5 Misfire
P0306 - Cylinder #6 Misfire
P0351 - Ignition Coil #1 Primary Circuit
P0352 - Ignition Coil #2 Primary Circuit
P0353 - Ignition Coil #3 Primary Circuit