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

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a flat surface and engage the parking brake.
• Disconnect the battery's negative terminal.

2. Inspect and Replace Spark Plugs

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the spark plug wires or ignition coils.
• Use a spark plug socket to remove each spark plug.
• Inspect each spark plug for signs of wear, fouling, or damage.
• If damaged, replace with OEM-spec spark plugs.
• Torque new spark plugs to manufacturer specifications (typically 13-15 lb-ft).

3. Check and Replace Ignition Coils

• Tools Required: Ratchet and socket set.
• Remove the ignition coils from the spark plug wells.
• Inspect for cracks or signs of damage.
• Replace any faulty ignition coils with OEM parts.
• Reinstall ignition coils and ensure they are seated properly.

4. Inspect and Clean Fuel Injectors

• Tools Required: Fuel injector cleaning kit (if applicable), basic hand tools.
• Remove the fuel rail to access the injectors.
• Inspect injectors for clogs or leaks.
• Clean injectors using a cleaning kit or replace with OEM injectors if necessary.
• Reinstall fuel rail ensuring proper sealing.

5. Check for Vacuum Leaks

• Tools Required: Vacuum gauge (optional).
• Inspect all vacuum lines for cracks or disconnections.
• Use a smoke machine or carburetor cleaner to identify leaks.
• Replace any damaged hoses or components found.

6. Perform Compression Test

• Tools Required: Compression tester.
• Remove spark plugs to access cylinders.
• Insert the compression tester into each cylinder.
• Crank the engine and record the compression readings.
• Compare readings to manufacturer specifications; consider cylinder head or gasket replacement if readings are low.