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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Replace Spark Plugs

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the spark plug wires or ignition coils.
• Using a spark plug socket, carefully remove the old spark plugs.
• Inspect the spark plug gap and replace with new plugs (ensure correct gap as per manufacturer specifications).
• Torque the new spark plugs to the specified value (usually around 13-16 lb-ft).
• Reconnect the ignition coils or spark plug wires.

3. Inspect and Replace Ignition Coils (if necessary)

• Tools Required: Socket set, multimeter.
• Remove the ignition coils from the engine.
• Test each ignition coil with a multimeter to check for resistance; replace any that are out of specifications.
• Install new ignition coils if necessary, ensuring they are seated properly.

4. Check Fuel Injectors

• Tools Required: Fuel pressure gauge, injector cleaning kit.
• Connect a fuel pressure gauge to the fuel rail to check for proper fuel pressure.
• If pressure is low, inspect the fuel filter and pump.
• Clean or replace any faulty fuel injectors as necessary.

5. Inspect Vacuum Lines

• Visually inspect all vacuum lines for cracks or disconnections.
• Replace any damaged vacuum hoses to ensure proper air-fuel mixture.

6. Perform Compression Test

• Tools Required: Compression tester.
• Remove spark plugs to facilitate testing.
• Insert the compression tester into each spark plug hole and crank the engine.
• Compare compression readings to manufacturer specifications; low compression may indicate internal engine issues.