how to fix P0300 random misfire code in Toyota Camry Eighth Generation (2018-present)?

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, fuel pressure gauge.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent any electrical shorts.

2. Inspect and Replace Spark Plugs

• Sub-steps:
  1. Remove the ignition coil cover if applicable.
  2. Disconnect the ignition coil connectors.
  3. Remove the ignition coils from the spark plugs.
  4. Unscrew and remove the spark plugs using a socket.
  5. Inspect the spark plugs for wear; replace if necessary with OEM or equivalent spark plugs.
  6. Torque the new spark plugs to the manufacturer’s specified torque (typically around 13-15 lb-ft).
  7. Reinstall the ignition coils and reconnect the connectors.

3. Check and Replace Ignition Coils

• Sub-steps:
  1. With the ignition coils removed, use a multimeter to test each coil’s primary and secondary resistance.
  2. Replace any faulty ignition coils with new OEM parts.
  3. Reinstall the ignition coils, ensuring they are securely seated and connectors are properly connected.

4. Inspect and Clean Fuel Injectors

• Sub-steps:
  1. Remove the fuel injector connectors and fuel rail (if applicable).
  2. Inspect the injectors for clogs or leaks.
  3. Clean the injectors using a professional injector cleaning kit or replace them if necessary.
  4. Reinstall the fuel rail and connectors, ensuring all connections are secure.

5. Test Fuel Pressure

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail service port.
  2. Turn the ignition to the "ON" position (do not start) and observe the pressure reading.
  3. Compare the readings to the manufacturer's specifications (typically around 50-60 psi for a Camry).
  4. If pressure is low, inspect the fuel pump and filter for issues.

6. Inspect for Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum lines and the intake manifold gasket for visible damage.
  2. Use a smoke machine or carburetor cleaner to detect any vacuum leaks.
  3. Replace any damaged vacuum lines or gaskets.