how to fix P0300 code on my Ford Mustang S550 (2015-2023)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, fuel pressure gauge, multimeter, vacuum gauge.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plugs

• Remove the ignition coil by unscrewing the bolts and disconnecting the electrical connector.
• Remove the spark plug using a spark plug socket.
• Inspect the spark plug for wear; if worn or fouled, replace with OEM specifications (typically NGK or Motorcraft).
• Reinstall the spark plug and torque to the manufacturer's specification (usually around 13-15 lb-ft).

3. Test and Replace Ignition Coils

• Use a multimeter to test the resistance of the ignition coils; compare readings against manufacturer specifications.
• If any coil is outside of the specified range, replace it with an OEM coil.
• Reinstall the ignition coils ensuring they are seated properly.

4. Inspect and Clean Fuel Injectors

• Remove the fuel rail and inspect the fuel injectors for clogs.
• Use a fuel injector cleaner to clean clogged injectors; if they are damaged, replace with OEM injectors.
• Reinstall the fuel rail and ensure proper sealing.

5. Check Fuel Pressure

• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position (without starting the engine) and check the fuel pressure against specifications (usually 50-60 psi for Mustang).
• If pressure is low, inspect the fuel pump and fuel filter; replace as necessary.

6. Inspect for Vacuum Leaks

• Use a vacuum gauge to measure engine vacuum at idle.
• If vacuum is low, use carburetor cleaner or a smoke machine to locate leaks around the intake manifold and hoses.
• Repair any identified leaks.