how to fix P0300 misfire code in Ford F-150 Fourteenth Generation (2021-present)

Learn how to diagnose and fix P0300 engine misfire in Ford F-150. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool down before beginning work.

2. Replace Spark Plugs

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the ignition coil(s) by unbolting them and disconnecting the electrical connector.
• Use the spark plug socket to remove the old spark plugs from the cylinder head.
• Inspect the spark plug gap and replace with new spark plugs, ensuring they are gapped to manufacturer specifications.
• Torque the new spark plugs to the specified value (typically around 13-15 lb-ft).
• Reinstall the ignition coils and reconnect the electrical connectors.

3. Check and Replace Ignition Coils (if necessary)

• If misfire persists, test the ignition coils with a multimeter to ensure they are functioning correctly.
• If faulty, remove the ignition coils by removing the retaining bolts and disconnecting the connectors.
• Install new ignition coils, ensuring they are seated properly, and reconnect the connectors.

4. Fuel Injector Inspection and Service

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail to check for proper fuel pressure.
• If pressure is low, inspect the fuel pump and fuel filter for issues.
• Clean or replace clogged fuel injectors as needed.

5. Vacuum Leak Inspection

• Visually inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
• Use a smoke machine or propane torch (safely) to detect vacuum leaks. Repair any leaks found.