how to diagnose P0301 misfire code on Ford Explorer Sixth Generation (2020-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is on a flat surface and the engine is cool.
• Disconnect the negative battery cable for safety.

2. Inspect and Replace Spark Plug

1. Remove the ignition coil from cylinder 1:
   • Unplug the electrical connector.
   • Remove the mounting bolts using a socket set.
2. Extract the spark plug using a spark plug socket.
3. Inspect the spark plug for wear or damage; replace if necessary.
   • Use a spark plug gap tool to ensure proper gap specifications.
4. Install the new or inspected spark plug:
   • Hand-tighten the spark plug, then torque to manufacturer specifications (typically around 13 ft-lbs).
5. Reinstall the ignition coil:
   • Secure it with bolts and reconnect the electrical connector.

3. Check and Replace Fuel Injector

1. Access the fuel injector for cylinder 1:
   • Remove any necessary components obstructing access (e.g., intake manifold).
2. Test the fuel injector operation:
   • Use a noid light to check for pulse signal.
   • If no signal is detected, trace wiring and check the injector driver circuit.
3. If the injector is faulty, remove the old injector:
   • Disconnect the electrical connector and fuel line.
   • Remove retaining clips and pull out the injector.
4. Install the new fuel injector:
   • Lubricate the O-ring with engine oil before installation.
   • Insert the new injector and secure it with clips.
5. Reconnect the fuel line and electrical connector.

4. Compression Testing

1. Remove the spark plug from cylinder 1.
2. Insert a compression gauge into the spark plug hole.
3. Crank the engine several times while observing the gauge.
4. Compare the reading to manufacturer specifications; replace the cylinder head gasket or perform further engine repairs if readings are low.