Cylinder #4 misfire. The cause is usually in the secondary circuit. (You can often smell the catalytic converter trying to process the unburned fuel. If so, that confirms your problem's electrical, not in your fuel system.) In earlier models, typical cause is high-resistance (bad, internally broken) spark plug wire. In later models, typical cause is a bad coil (coil on plug--COP) for engines so equipped.
Trouble code P0304 means:Cylinder 4 misfire detected
Trouble code P0304 means:Cylinder 4 misfire detected
Trouble code P0304 means:Cylinder 4 misfire detected
Trouble code P0304 means:Cylinder 4 misfire detected
Trouble code P0304 means:Cylinder 4 misfire detected
Trouble code P0304 means:Cylinder 4 misfire detected
Trouble code P0304 means: Cylinder 4 Misfire Detected
Trouble code P0304 means:Cylinder 4 misfire detected
Trouble code P0303 means:Cylinder 3 misfire detected Trouble code P0304 means:Cylinder 4 misfire detected
Trouble code P0304 means:Cylinder 4 misfire detected
Trouble code P0304 means: Cylinder 4 Misfire Detected
Trouble code P0304 means: Cylinder 4 Misfire Detected