how to diagnose a misfire in my Ford F-150 Fourteenth Generation (2021-present) with code P0301?

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, compression tester, multimeter, torque wrench.
• Disconnect the battery to ensure safety before working on electrical components.

2. Replace Spark Plug

• Sub-steps:
  1. Remove the ignition coil from cylinder 1 by unscrewing the bolts and disconnecting the electrical connector.
  2. Use a spark plug socket to remove the spark plug from the cylinder head.
  3. Install the new spark plug by hand to avoid cross-threading, then torque to the manufacturer’s specifications (usually around 13 lb-ft).
  4. Reinstall the ignition coil and reconnect the electrical connector.

3. Test and Replace Ignition Coil (if necessary)

• Sub-steps:
  1. Using a multimeter, check the resistance of the ignition coil (compare to specifications in the service manual).
  2. If the ignition coil is faulty, remove it from the engine.
  3. Install a new ignition coil and reconnect all connectors securely.

4. Clean or Replace Fuel Injector (if needed)

• Sub-steps:
  1. Disconnect the fuel injector connector and remove the fuel line from the injector.
  2. Remove the fuel injector from the cylinder head.
  3. Inspect the injector for clogs. Clean it with a fuel injector cleaner or replace it with a new one.
  4. Reinstall the injector and reconnect the fuel line and electrical connector.

5. Compression Test (if previous steps do not resolve misfire)

• Sub-steps:
  1. Remove the spark plug from cylinder 1.
  2. Insert the compression tester into the spark plug hole and crank the engine.
  3. Record the reading and compare it to manufacturer specifications.
  4. If compression is low, further investigation may be needed for internal engine issues.