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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the engine is cool before starting any repairs.

2. Inspect and Replace Ignition Components

• Tools Required: Socket set, torque wrench, spark plug socket, dielectric grease.
• Remove the engine cover if equipped.
• Disconnect the ignition coils' electrical connectors and remove the bolts securing them.
• Pull the ignition coils out and inspect them for damage; replace if necessary.
• Remove the spark plugs using the spark plug socket and inspect for wear or fouling; replace if necessary.
• Apply dielectric grease to the new ignition coils' connectors.
• Install new spark plugs and torque to the manufacturer’s specifications (usually around 13-15 lb-ft).
• Reinstall the ignition coils and connect electrical connectors.

3. Check and Repair Fuel System

• Tools Required: Fuel pressure gauge, line wrenches.
• Connect the fuel pressure gauge to the Schrader valve on the fuel rail.
• Turn the ignition to the ON position (do not start the engine) to check fuel pressure; compare readings to manufacturer specifications.
• If pressure is low, inspect the fuel pump, filter, and fuel lines for blockages or failures.
• Replace the fuel filter if it’s clogged or replace the fuel pump if it’s defective.

4. Inspect for Vacuum Leaks

• Tools Required: Smoke machine or carburetor cleaner.
• With the engine running, use the smoke machine to detect leaks in the intake manifold or vacuum hoses.
• If using carburetor cleaner, spray around suspected areas and listen for changes in engine RPM indicating a leak.
• Replace any damaged hoses or gaskets discovered during inspection.

5. Perform Compression Test

• Tools Required: Compression tester.
• Remove all spark plugs and insert the compression tester into the spark plug wells.
• Crank the engine several times and record the compression readings for each cylinder.
• Compare the readings to manufacturer specifications; replace any cylinder with significantly lower compression.