how to fix P0301 misfire code in Ford Mustang S650 (2024-Present)

Solution

1. Preparation

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

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1 using a socket.
• Extract the spark plug using a spark plug socket.
• Inspect the spark plug for wear; if worn or fouled, replace it with a new spark plug (use OEM specifications).
• Reinstall the spark plug and torque it to the manufacturer's specifications (typically around 13-15 lb-ft).
• Reinstall the ignition coil securely.

3. Test and Replace Ignition Coil (if necessary)

• If the spark plug appears fine, test the ignition coil using a multimeter for proper resistance.
  • Primary resistance: typically between 0.5 to 1.5 ohms.
  • Secondary resistance: should be between 6,000 to 15,000 ohms.
• If the ignition coil is faulty, replace it with a new OEM ignition coil.
• Reconnect the coil after replacement.

4. Inspect and Test Fuel Injector

• Remove the fuel injector connector for cylinder 1.
• Use a fuel injector tester to check the injector's operation.
• If the injector does not operate or is clogged, replace it with a new OEM fuel injector.
• Reconnect the fuel injector connector after replacement.

5. Perform Compression Test

• Remove the spark plug from cylinder 1.
• Insert the compression tester into the spark plug hole.
• Crank the engine for a few seconds and note the compression reading.
• Compare the compression reading to specifications (usually around 150-200 psi).
• If compression is low, further investigation into valve or piston issues is necessary.

6. Reconnect Battery

• Once repairs are complete, reconnect the negative battery terminal.