how to fix P0300 misfire code in Ford F-150 14th Generation (2021-2024)

Learn how to diagnose and fix P0300 engine misfire in Ford F-150 (2021-2024). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery cable to ensure safety.

2. Replace Spark Plugs and Ignition Coils

• Tools Required: Socket set, torque wrench, dielectric grease
• Remove the engine cover if applicable.
• Disconnect the electrical connectors from the ignition coils.
• Remove the ignition coils by unbolting them from the engine.
• Remove the old spark plugs using a spark plug socket.
• Install new spark plugs, ensuring they are gapped correctly (follow manufacturer specifications).
• Apply dielectric grease to the ignition coil boots to prevent moisture ingress.
• Reinstall the ignition coils and reconnect the electrical connectors.

3. Inspect and Repair Fuel System

• Tools Required: Fuel pressure gauge, line wrench
• Locate the fuel pressure test port on the fuel rail.
• Connect the fuel pressure gauge and turn the ignition to the "ON" position without starting the engine; check for correct pressure (refer to manufacturer specifications).
• If pressure is low, inspect the fuel filter and fuel pump for blockages or failures. Replace as necessary.

4. Check for Air Intake Leaks

• Tools Required: Smoke machine or carburetor cleaner
• Visually inspect the air intake hoses and connections for cracks or loose fittings.
• Use a smoke machine to detect leaks in the intake system; alternatively, spray carburetor cleaner around the intake manifold while observing for RPM changes.
• Repair or replace any leaking components.

5. Compression Test

• Tools Required: Compression gauge
• Remove all spark plugs and disable the ignition system.
• Insert the compression gauge into the spark plug holes and crank the engine.
• Compare the readings from each cylinder to manufacturer specifications. If any cylinder is significantly lower, further investigation into that cylinder may be necessary (valve issues, piston rings).