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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the battery to ensure safety while working on the engine.

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 wear, carbon buildup, or damage. Replace if necessary.
• Torque the new spark plug to the manufacturer's specifications (typically around 13-15 lb-ft).
• Reinstall the ignition coil, ensuring it is securely connected.

3. Test and Replace Ignition Coil (if needed)

• If the spark plug is in good condition, test the ignition coil using a multimeter (check for primary and secondary resistance).
• If the ignition coil is faulty, replace it with a new one.
• Reconnect the ignition coil and ensure all connections are secure.

4. Check Fuel Injector Function

• Disconnect the fuel injector connector for cylinder 1.
• Use a noid light to check for injector pulse while cranking the engine.
• If no signal is detected, inspect the wiring and connector for damage.
• If the injector is faulty, replace it with a new one, reconnect the connector, and ensure it is securely seated.

5. Perform Compression Test

• Remove the spark plug from cylinder 1.
• Insert a compression gauge into the spark plug hole and crank the engine.
• Record the compression reading. It should be within the manufacturer's specified range (typically 150-200 psi).
• If the compression is low, further investigation is needed for internal engine issues.