how to fix P0300 random misfire code in Toyota Camry XV40 (2007-2011)

Solution

1. Preparation

• Gather tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace Spark Plugs

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coils by unbolting them and disconnecting the electrical connectors.
• Use a spark plug socket to remove the spark plugs.
• Inspect old spark plugs for signs of wear, carbon buildup, or oil fouling.
• Install new spark plugs, ensuring they are gapped correctly (typically 0.043 inches for this model).
• Torque plugs to manufacturer specifications (typically 13 lb-ft).

3. Inspect and Replace Ignition Coils

• Test each ignition coil’s primary and secondary resistance with a multimeter.
• Replace any ignition coils that do not meet specifications.
• Reinstall ignition coils securely and reconnect electrical connectors.

4. Check and Clean Fuel Injectors

• Tools Required: Fuel injector cleaning kit or solvent.
• Remove the fuel rail to access the injectors.
• Clean fuel injectors using an appropriate cleaning kit or solvent to remove any deposits.
• Reinstall fuel injectors and fuel rail, ensuring proper sealing with O-rings.

5. Check for Vacuum Leaks

• Perform a smoke test to identify any vacuum leaks.
• Visually inspect all vacuum lines and gaskets for wear or damage.
• Replace any damaged hoses or gaskets.

6. Compression Test

• Tools Required: Compression tester.
• Remove the ignition coils and spark plugs to access the cylinders.
• Insert the compression tester into the spark plug hole and crank the engine.
• Record the compression readings; they should be within the manufacturer’s specifications.