[CREWZIN]

A couple of TSB's (Technical Service Bulletins) were issued for your code.

# TSB #1802802 -- MIL ILLUMINATION - MISFIRE DIAGNOSTIC TROUBLE CODE (DTCS) P0300, P0301, P0302, P0303, P0304. *TT (NHTSA ID #10016602, AUGUST 04 2005)


# TSB #1801405 -- FLASH: MIL ILLUMINATION DIAGNOSTIC TROUBLE CODES (DTC/DIAGNOSTIC TROUBLE CODE) P0300, P0301, P0302, P0302, P0303, P0304, P0305, P0306-COLD START MISFIRE. *SC (NHTSA ID #10013716, MARCH 25 2005)


Some more stuff I found:

Message:
My dakota puts up the code p0304. Ive had the injectors cleaned, the plugs and wires replaced and the #4 injector has been checked out and is just fine. What else could cause the misfire? It runs great going down the road but the misfire occurs when it's idleing. Could it be a sensor?

Message:
had the same problem blew a can of throttle body cleaner through the throttle body with engine running problem went away hasn't come back that was 4 months ago. I think it was sticky valve tried same things you did as well $5 can fixed problem

More to read:

P0304 Code - Cylinder #4 Misfire
Technical Description

Cylinder #4 Misfire Detected
What does that mean?

A P0304 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #4.
Symptoms
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 P0304 may mean that one or more of the following has happened:

* Faulty spark plug or wire
* Faulty coil (pack)
* Faulty oxygen sensor(s)
* Faulty fuel injector
* Burned exhaust valve
* Faulty catalytic converter(s)
* Running out of fuel
* Poor compression
* 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.