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

Solution

1. Preparation

• Gather tools and components needed for repair.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool down before starting work.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1 using a socket set.
• Carefully pull out the spark plug using a spark plug socket.
• Inspect the spark plug for signs of wear or damage (e.g., fouling, electrode wear).
• If necessary, replace the spark plug with a new one that meets OEM specifications (typically a Motorcraft SP-546 or equivalent).
• Torque the new spark plug to the manufacturer's specified value (usually 13-15 lb-ft).

3. Check and Replace Ignition Coil

• If the spark plug is in good condition, test the ignition coil using a multimeter for proper resistance.
• If faulty, replace the ignition coil with a compatible unit (e.g., Motorcraft DG-508 or equivalent).
• Reinstall the ignition coil and ensure it's securely seated.

4. Inspect Fuel Injector

• Disconnect the electrical connector from the fuel injector for cylinder 1.
• Test the injector with a noid light to verify it’s receiving the correct signal.
• If not functioning, replace with a new fuel injector that matches OEM specifications.
• After replacement, ensure all connections are secured.

5. Compression Test (if misfire persists)

• Remove the spark plug and ignition coil again for access.
• Insert a compression gauge into cylinder 1 and crank the engine.
• Compare the reading to the manufacturer's specifications (usually around 150-200 psi).
• If low compression is detected, further investigation of engine internals may be required.