how to fix P0304 code on my Ford F-150 14th Generation (2021-2024)?

Learn how to diagnose and fix P0304 cylinder 4 misfire in Ford F-150 14th Generation. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts. Disconnect the battery to ensure safety.
• Tools Required: Socket set, torque wrench, OBD-II scanner, multimeter, compression tester, basic hand tools.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 4:
  • Disconnect the electrical connector.
  • Remove the retaining bolt(s) and lift the coil out.
• Remove the old spark plug using a spark plug socket:
  • Check the spark plug gap and replace it if necessary with the correct type.
• Install the new spark plug:
  • Torque to specifications (typically 12-15 lb-ft).
• Reinstall the ignition coil:
  • Ensure it is seated properly and reconnect the electrical connector.

3. Inspect/Replace Ignition Coil

• If the ignition coil was found faulty during diagnostics:
  • Remove the ignition coil as previously described.
  • Replace it with a new coil designed for your F-150.
  • Reinstall by reversing the removal steps and ensuring proper connections.

4. Check/Replace Fuel Injector

• If a clog or malfunction is suspected:
  • Remove the injector rail and take out the fuel injector for cylinder 4.
  • Clean the injector using a professional cleaning kit or replace with a new injector.
• Reinstall the injector and ensure all connections are secure.

5. Conduct Compression Test

• If compression was low in cylinder 4:
  • Investigate the cause (e.g., valve issues, head gasket).
  • Repair any underlying mechanical issues as required.