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

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

Solution

1. Preparation

• Gather required tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, dielectric grease.
• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Locate the spark plug for cylinder four.
  3. Remove the ignition coil by unscrewing the retaining bolt and gently pulling it off.
  4. Use a spark plug socket to remove the spark plug from cylinder four.
  5. Inspect the old spark plug for signs of wear, carbon buildup, or oil fouling.
  6. Install the new spark plug into cylinder four, tightening to the manufacturer's specified torque (typically around 13-15 lb-ft).
  7. Apply dielectric grease to the ignition coil boot before reinstalling.

3. Replace Ignition Coil

• Tools Required: Socket set.
• Sub-steps:
  1. Remove the ignition coil from cylinder four if not already done.
  2. Install the new ignition coil for cylinder four.
  3. Secure the coil with the retaining bolt and reconnect the wiring harness.

4. Test Fuel Injector

• Tools Required: Fuel injector tester (if available).
• Sub-steps:
  1. Disconnect the fuel injector connector for cylinder four.
  2. Use a fuel injector tester to check the injector’s operation.
  3. Replace the fuel injector if it is not functioning properly.

5. Reassemble and Reconnect

• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Start the engine and ensure there are no additional fault codes.