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

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface with the engine off.
• Gather all necessary tools and safety equipment.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench, gap tool
• Remove the ignition coil from cylinder 1:
  • Unplug the electrical connector.
  • Remove the mounting bolts and lift out the coil.
• Remove the spark plug using a spark plug socket:
  • Inspect the plug for carbon buildup or damage.
  • If necessary, replace with a new spark plug, ensuring the gap is set to manufacturer specifications (usually around 0.030-0.035 inches for Mustangs).
• Reinstall the spark plug and torque to the manufacturer’s specification (typically 12-15 lb-ft).

3. Inspect and Replace Ignition Coil

• If the spark plug is in good condition, test the ignition coil:
  • Swap the ignition coil with one from a different cylinder.
  • Clear the DTC and run the engine to see if the misfire moves to the new cylinder.
• If the misfire follows the coil, replace it with a new, OEM-standard ignition coil.

4. Check Fuel Injector

• Tools Required: Noid light, fuel pressure gauge
• Inspect the fuel injector for proper operation.
• Use a noid light to check for signal to the fuel injector while cranking the engine.
• If the injector is not firing, replace it with a new unit.

5. Compression Test

• If misfire persists, perform a compression test on cylinder 1:
  • Remove the spark plug and install the compression tester.
  • Crank the engine and record the compression reading.
  • Compare with specifications (typically 150-200 psi).
• If compression is low, further investigation into the engine internals may be necessary (e.g., leaking valves, head gasket issues).