how to diagnose a P0304 code on my Ford F-150 12th Generation (2009-2014)?

Learn how to diagnose and fix P0304 cylinder 4 misfire in Ford F-150 (2009-2014). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the battery to avoid any electrical shorts.

2. Replace Spark Plug

• Remove the Spark Plug:
  • Use a spark plug socket and ratchet to remove the spark plug from cylinder 4.
• Install New Spark Plug:
  • Check the gap on the new spark plug using a feeler gauge (should be within manufacturer specifications).
  • Install the new spark plug and torque it to the manufacturer’s specification (typically around 13-15 ft-lbs).

3. Replace Ignition Coil (if necessary)

• Remove Ignition Coil:
  • Disconnect the electrical connector from the ignition coil.
  • Remove the retaining screws and lift the ignition coil out of the well.
• Install New Ignition Coil:
  • Position the new ignition coil in place and secure it with screws.
  • Reconnect the electrical connector.

4. Clean or Replace Fuel Injector (if necessary)

• Remove Fuel Injector:
  • Disconnect the fuel rail and remove the fuel injector from cylinder 4.
• Clean or Replace:
  • If cleaning, use injector cleaner and follow the manufacturer’s instructions; otherwise, install a new injector.
• Reinstall Fuel Injector:
  • Ensure it is seated correctly and reattach the fuel rail.

5. Reconnect Battery and Test

• Reconnect the battery.
• Start the engine and observe for any misfires or warning lights.