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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shock.

2. Inspect and Replace Spark Plugs

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coils by unscrewing the mounting bolts and gently pulling them out.
• Use a spark plug socket to remove the spark plugs; inspect for wear or damage.
• Replace with new spark plugs, ensuring they are gapped to manufacturer specifications (typically 0.043 inches).
• Reinstall the ignition coils, tightening to the manufacturer's torque specifications (usually around 10-15 ft-lbs).

3. Check and Replace Ignition Coils

• Tools Required: Socket set, multimeter (optional).
• If any coils are found to be faulty during inspection, replace them with new coils.
• Disconnect the electrical connector and remove the coil by unscrewing it.
• Install the new ignition coil and reconnect the electrical connector.

4. Inspect and Clean Fuel Injectors

• Tools Required: Fuel injector cleaning kit, safety goggles, gloves.
• Remove the fuel rail by unscrewing the mounting bolts and disconnecting the fuel lines (be cautious of fuel spillage).
• Remove the fuel injectors and clean them using a fuel injector cleaning kit or replace them if they are clogged.
• Reinstall the fuel injectors and the fuel rail, ensuring all connections are secure.

5. Check for Vacuum Leaks

• Tools Required: Smoke machine or carburetor cleaner.
• Visually inspect all vacuum hoses for cracks or loose connections.
• Use a smoke machine or spray carburetor cleaner around the intake manifold and hoses while the engine is running; listen for changes in engine RPM to identify leaks.
• Replace any damaged hoses.