P0306 Misfire Diagnosis: 2004 Dodge Caravan SXT 3.3L Engine Fix
I'm experiencing a persistent engine light with code P0306 on my 2004 Dodge Caravan SXT with a 3.3L engine. I've already replaced the spark plug, spark plug wires, ignition coil, and fuel injector for cylinder 6. After driving approximately 50 km, the same misfire code continues to appear. Freeze frame data: - Fuel System 1: CL (Cooled) - Fuel System 2: N/A - Load Calculation: 26.3% - Engine Coolant Temperature (ECT): 192°F - Short Term Fuel Trim B1: 0% - Long Term Fuel Trim B1: -5.5% - Manifold Absolute Pressure (MAP): 10 inHg - Engine RPM: 175 - Vehicle Speed: 9 MPH - Spark Advance: 20.
Are there any other diagnostic trouble codes present? Ensure you're using the correct spark plugs—SPRE14PPL5 is recommended as plug type matters. Has the TSB 18-18-04 been completed? I recall a reflash procedure for misfire monitoring can help reset the system. Is cylinder #6 actually firing? Check if the old spark plug was black, wet, dry, tan, or damaged—this indicates combustion issues. A compression test on the front bank (which includes cylinder 6) is advised—it's easier and sufficient to diagnose this issue. Note: Cylinder 6 is located on the driver’s side of the front bank.