how to diagnose P0300 code on my Toyota RAV4 XA50 (2019-2024)?

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 shorts.

2. Inspect and Replace Spark Plugs

• Tools Required: Socket set, torque wrench.
• Remove the ignition coils using the socket set.
• Extract the spark plugs from each cylinder and inspect for wear.
• Replace spark plugs if they are worn or fouled (use OEM parts for best results).
• Reinstall the ignition coils and torque to manufacturer specifications (typically 12-15 Nm).

3. Test and Replace Ignition Coils (if necessary)

• Tools Required: Multimeter.
• Use a multimeter to test the resistance of each ignition coil.
• Replace any faulty ignition coils with OEM parts.
• Reconnect the ignition coils.

4. Check Fuel System

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position (without starting) to check fuel pressure.
• Ensure pressure is within specifications (typically 40-50 psi for most vehicles).
• If pressure is low, inspect the fuel pump and filter and replace as needed.

5. Inspect Intake and Vacuum System

• Tools Required: Visual inspection tools (flashlight, etc.).
• Visually inspect the air intake system for any signs of leaks or blockages.
• Check all vacuum hoses for cracks or disconnections.
• Repair or replace any faulty components.