how to fix the P0301 misfire code in my Ford Mustang S550 (2015-2023)?

Solution

1. Preparation

• Gather tools: OBD-II scanner, spark plug socket, ratchet and extensions, multimeter, compression tester, vacuum gauge, and basic hand tools.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if necessary to access the spark plug.
  2. Use the spark plug socket to remove the spark plug from cylinder 1.
  3. Inspect the spark plug for signs of wear, carbon buildup, or damage.
  4. If damaged, replace it with a new spark plug that matches OEM specifications.
  5. Torque the new spark plug to the manufacturer’s specifications (typically around 13-15 lb-ft).

3. Inspect and Replace Ignition Coil

• Sub-steps:
  1. Remove the ignition coil connector from the ignition coil on cylinder 1.
  2. Unscrew the ignition coil from the cylinder head using the appropriate socket.
  3. Inspect the ignition coil for cracks or signs of overheating.
  4. Replace with a new ignition coil if necessary.
  5. Reinstall the ignition coil and reconnect the electrical connector.

4. Check Fuel Injector

• Sub-steps:
  1. Disconnect the fuel injector connector for cylinder 1.
  2. Use a multimeter to check for voltage at the injector connector with the ignition on (should be approximately 12V).
  3. If voltage is present, test the injector operation with a noid light or replace if it fails to activate.
  4. Reconnect the injector connector when finished.

5. Perform Compression Test

• Sub-steps:
  1. Remove the spark plug for cylinder 1.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine for several seconds and read the compression pressure.
  4. Compare the reading to the manufacturer's specifications (typically 150-200 psi).
  5. If compression is low, further diagnose for potential internal engine issues.