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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the engine is cool before starting work.
• Disconnect the negative terminal of the battery to prevent electrical shock.

2. Inspect and Replace Spark Plugs

• Remove the ignition coil covers if applicable.
• Remove spark plugs using a spark plug socket.
• Inspect the spark plugs for wear; replace them if they are worn or fouled.
• Install new spark plugs, ensuring they are gapped correctly (typically 0.043 inches for Camry).
• Reinstall ignition coil covers.

3. Test and Replace Ignition Coils

• Remove the ignition coils from each cylinder.
• Test each coil with a multimeter (measure resistance; should be within manufacturer specifications).
• Replace any faulty ignition coils with OEM or high-quality aftermarket parts.
• Reinstall the ignition coils securely.

4. Inspect and Clean Fuel Injectors

• Use a fuel pressure gauge to check fuel pressure; it should be within the specified range (typically around 40-50 psi).
• If pressure is low, check the fuel filter and fuel pump condition.
• Clean or replace clogged fuel injectors using a fuel injector cleaner.
• Reinstall fuel injectors and ensure they are seated correctly.

5. Check for Vacuum Leaks

• Inspect all vacuum hoses and connections visually.
• Use a smoke machine or spray carburetor cleaner around the intake manifold and hoses to identify leaks.
• Replace any damaged hoses or seals.

6. Reassemble and Reconnect Battery

• Ensure all components are reassembled correctly.
• Reconnect the negative battery terminal.
• Start the engine and allow it to idle.