how to fix P0300 random misfire code on Ford Explorer Fifth Generation (2011-2019)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before beginning work.

2. Inspect and Replace Spark Plugs

1. Remove the engine cover (if applicable).
2. Use a socket wrench to remove the spark plug wires or ignition coils.
3. Extract the spark plugs using a spark plug socket and ratchet.
4. Inspect the spark plugs for wear; replace if worn or if the gap is incorrect.
5. Install new spark plugs, ensuring they are gapped correctly according to specifications (usually around 0.054 inches for this model).
6. Reconnect spark plug wires or ignition coils.

3. Check and Replace Ignition Coils

1. Remove the ignition coils from the spark plugs.
2. Inspect for cracks or carbon tracking on the coils.
3. If necessary, replace faulty ignition coils with new units.
4. Reinstall ignition coils securely onto the spark plugs.

4. Inspect Fuel Injectors

1. Locate fuel injectors and inspect for leaks or damage.
2. If faulty, remove the fuel rail to access the injectors.
3. Replace any defective fuel injectors.
4. Reinstall the fuel rail and ensure it is properly connected.

5. Check for Vacuum Leaks

1. Inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
2. Use a smoke machine or carb cleaner spray to detect leaks while the engine is idling.
3. Repair or replace any damaged hoses or gaskets found during inspection.

6. Test Fuel System

1. Attach a fuel pressure gauge to the fuel rail.
2. Start the engine and check if fuel pressure is within the specified range (typically 30-50 psi).
3. If pressure is low, check the fuel pump and filter for issues and replace if necessary.