how to resolve P0301 misfire code in Ford Explorer Fifth Generation (2011-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on the electrical system.
• Allow the engine to cool down.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 1:
  • Disconnect the electrical connector.
  • Unbolt the coil using a socket wrench.
• Remove the spark plug with a spark plug socket:
  • Turn counterclockwise to loosen, then remove.
• Inspect the old spark plug for signs of wear or fouling.
• Install the new spark plug:
  • Hand-thread the spark plug into the cylinder head.
  • Tighten to the manufacturer’s specified torque (typically around 13 ft-lbs).
• Reinstall the ignition coil:
  • Replace and tighten the bolts securely.
  • Reconnect the electrical connector.

3. Test Ignition Coil

• If the spark plug replacement did not resolve the issue, test the ignition coil:
  • Swap the ignition coil from cylinder 1 with another cylinder (e.g., cylinder 2).
  • Clear the error codes and run the engine.
  • Check if the misfire code follows the ignition coil to the new cylinder.

4. Inspect Fuel Injector

• If the misfire persists, check the fuel injector for cylinder 1:
  • Remove the fuel rail (ensure fuel system pressure is relieved first).
  • Inspect the injector for clogs or malfunctions.
  • Replace the injector if necessary.
• Reinstall the fuel rail and reconnect any lines or electrical connectors.

5. Perform Compression Test

• If the fuel injector is functioning correctly, perform a compression test:
  • Remove the spark plug from cylinder 1.
  • Insert the compression gauge and crank the engine.
  • Compare the reading to the manufacturer's specifications (typically around 120-150 psi).
• If compression is low, further investigation into the engine's internal components may be necessary.