what does it mean when my Ford F-150 has a P0303 misfire code

Learn how to diagnose and fix P0303 cylinder 3 misfire in Ford F-150. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather the necessary tools and parts.
• Disconnect the battery negative terminal to prevent electrical shorts during repair.
• Allow the engine to cool if it has been running.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 3.
  • Tools: Socket set, torque wrench.
• Remove the spark plug using a spark plug socket.
  • Inspect for wear, carbon buildup, or damage; replace if necessary.
• Install a new spark plug, ensuring it is properly gapped according to manufacturer specifications.
  • Torque the spark plug to the recommended value (typically 13-15 lb-ft).

3. Test and Replace Ignition Coil

• Test the ignition coil using a multimeter to check for proper resistance values.
• If faulty, remove the ignition coil and replace it with a new one.
  • Tools: Socket set.
• Reattach the ignition coil to the spark plug.

4. Inspect and Clean Fuel Injector

• Remove the fuel injector from cylinder 3 using the appropriate tools.
  • Tools: Socket set.
• Clean the injector using a fuel injector cleaning kit or replace it if clogged.
• Reinstall the fuel injector and ensure it is seated properly.

5. Reconnect Battery and Clear Codes

• Reconnect the battery negative terminal.
• Use the OBD-II scanner to clear the P0303 code and any other stored codes.