how to fix code P0300 in my Toyota RAV4 Fourth Generation (2013-2018)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative terminal of the battery to prevent electrical shorts.
• Allow the engine to cool completely before starting work.

2. Replace Spark Plugs

• Tools Required: Socket set, torque wrench, gap gauge
• Remove the engine cover (if applicable) by unscrewing any retaining bolts.
• Use a socket wrench to remove the old spark plugs.
• Inspect the old plugs for signs of wear (carbon build-up, oil, etc.).
• Check the gap on the new spark plugs using a gap gauge, and adjust to manufacturer specifications if necessary.
• Install the new spark plugs, tightening them to the manufacturer's torque specifications (usually around 13-15 lb-ft).
• Reinstall the engine cover.

3. Replace Ignition Coils

• Tools Required: Socket set, torque wrench
• Disconnect the electrical connector from the ignition coil.
• Remove the bolt securing the ignition coil using a socket wrench.
• Carefully pull the ignition coil out of the spark plug hole.
• Install the new ignition coil and tighten it to manufacturer specifications (typically 7-9 lb-ft).
• Reconnect the electrical connector.
• Repeat this process for all affected cylinders as indicated by diagnostic codes.

4. Inspect and Repair Fuel System

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition on (do not start the engine) and check the fuel pressure; it should meet manufacturer specifications (usually around 30-40 psi).
• If pressure is low, check the fuel pump and fuel filter for clogs or malfunctions. Replace as necessary.
• Ensure all fuel lines are secure and free of leaks.

5. Vacuum Leak Inspection

• Tools Required: Smoke machine or carburetor cleaner
• Use a smoke machine to check for vacuum leaks, or spray carburetor cleaner around vacuum lines while the engine is running.
• If the engine RPM changes, there is a vacuum leak that needs to be repaired.
• Replace any damaged vacuum lines or components.