how to fix P0303 code in Ford F-150 12th Generation (2009-2014)

Learn how to diagnose and fix P0303 cylinder 3 misfire in Ford F-150 12th Generation (2009-2014). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shock.
• Allow the engine to cool down.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coil from cylinder 3 by unscrewing the retaining bolts and disconnecting the electrical connector.
• Use a spark plug socket to remove the spark plug from cylinder 3. Inspect for fouling or damage.
• Replace with a new spark plug, ensuring it is gapped to manufacturer specifications (typically around 0.054 inches).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test and Replace Ignition Coil (if necessary)

• If the spark plug appears fine, test the ignition coil using a multimeter.
• Check the primary and secondary resistance according to manufacturer specifications.
• If out of range, replace the ignition coil with a new one and reinstall.

4. Inspect Fuel Injector

• Tools Required: Fuel injector removal tool, safety goggles.
• Disconnect the fuel injector connector and remove the fuel rail if necessary.
• Use a fuel injector cleaning kit to check for proper operation and flow.
• Replace the fuel injector for cylinder 3 if it is faulty or clogged.

5. Reassemble and Reconnect

• Reinstall any components that were removed, ensuring all connections are secure.
• Reconnect the negative battery terminal.