how to fix P0300 code in Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

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

2. Inspect and Replace Spark Plugs

1. Remove Engine Cover: Use a socket set to remove bolts securing the engine cover.
2. Access Spark Plugs: Disconnect ignition coils by removing the clips and unscrewing them.
3. Remove Spark Plugs: Use a spark plug socket to carefully unscrew and remove the spark plugs.
4. Install New Spark Plugs: Apply anti-seize compound to the threads of new spark plugs, torque to manufacturer specifications (typically around 13-16 lb-ft).
5. Reassemble Ignition Coils: Reinstall ignition coils and secure them with screws.

3. Check and Replace Ignition Coils

1. Remove Ignition Coils: After spark plug replacement, if misfire persists, remove the ignition coils.
2. Test Ignition Coils: Use a multimeter to check for proper resistance (consult service manual for specifications). Replace any faulty coils.
3. Reinstall Ignition Coils: Secure the new or tested coils in place.

4. Inspect and Clean Fuel Injectors

1. Remove Fuel Injector Rail: Disconnect the fuel line with a fuel line disconnect tool and remove bolts securing the rail.
2. Inspect Injectors: Check for clogs or leaks. Clean injectors using a fuel injector cleaning kit if necessary.
3. Reinstall Injector Rail: Ensure all seals are intact and reinstall the rail.

5. Check Vacuum Hoses

1. Inspect Hoses: Visually inspect all vacuum hoses connected to the intake manifold for signs of wear or damage.
2. Replace Damaged Hoses: If any hoses are cracked or disconnected, replace them with OEM parts.