how to fix P0301 misfire code on Ford Mustang S550 (2015-2023)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1:
  • Disconnect the electrical connector.
  • Unscrew the coil using the socket set and remove it.
• Remove the spark plug from cylinder 1:
  • Use a spark plug socket to unscrew the spark plug.
  • Inspect the spark plug for wear or fouling; replace if necessary.
• Install a new spark plug:
  • Torque the spark plug to manufacturer's specification (typically around 13-20 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Check and Replace Ignition Coil (if necessary)

• If the ignition coil tested out of specification, replace it:
  • Remove the faulty ignition coil as described above.
  • Install the new ignition coil, ensuring it is seated properly.
  • Reconnect the electrical connector.

4. Fuel Injector Inspection

• Inspect the fuel injector for cylinder 1:
  • Remove the fuel rail if necessary to access the injector.
  • Check for leaks and clean the injector if dirty; replace if malfunctioning.
• Reassemble the fuel rail and ensure all connections are secure.

5. Compression Test

• Use a compression tester:
  • Remove the spark plug again.
  • Insert the compression tester into the spark plug hole.
  • Crank the engine and record the compression reading.
• Compare the result to manufacturer specifications; if low, further investigation is needed.