how to address P0304 misfire code on my Ford F-150 13th Generation (2015-2020)

Learn how to diagnose and fix P0304 cylinder 4 misfire in Ford F-150 (2015-2020). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.

2. Remove the Ignition Coil and Spark Plug

• Tools Needed: Socket set, torque wrench, ratchet.
• Remove the engine cover if present.
• Disconnect the electrical connector from the ignition coil.
• Remove the bolts holding the ignition coil in place and pull it out.
• Use a spark plug socket to remove the spark plug from cylinder 4.

3. Inspect and Replace Components

• Spark Plug Inspection:

  • Examine the spark plug for signs of wear, fouling, or damage.
  • If necessary, replace the spark plug with a new one, ensuring it is gapped correctly (typically 0.054 inches for F-150).

• Ignition Coil Inspection:

  • Inspect the ignition coil for signs of arcing or damage.
  • Replace the ignition coil if it appears faulty.

4. Check and Clean the Fuel Injector

• Tools Needed: Fuel injector cleaning kit or replacement injector.
• Disconnect the fuel injector connector.
• Remove the injector from the rail by unlatching the clips.
• Clean the injector using a fuel injector cleaner or replace it if necessary.

5. Reassemble Components

• Reinstall the spark plug and torque it to the manufacturer’s specifications (typically around 13 lb-ft).
• Reinstall the ignition coil and torque the mounting bolts to specification (usually around 7 lb-ft).
• Reconnect the electrical connectors for the ignition coil and fuel injector.
• Reinstall the engine cover if it was removed.

6. Final Steps

• Reconnect the battery.
• Start the engine and let it idle for a few minutes.