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

Solution

1. Preparation

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

2. Inspect Spark Plugs

• Tools Required: Socket set, torque wrench
• Remove the ignition coil cover if applicable.
• Remove spark plugs using a socket wrench.
• Inspect each spark plug for signs of wear or fouling.
  • If damaged, replace with OEM equivalent spark plugs.
• Torque new spark plugs to the manufacturer's specifications (typically around 13-15 lb-ft).

3. Test Ignition Coils

• Tools Required: Multimeter
• Disconnect the electrical connector from each ignition coil.
• Set the multimeter to measure resistance.
• Check the primary and secondary resistance of each coil.
• Replace any coils that fall outside the specified resistance range.

4. Check Fuel Injectors

• Tools Required: Fuel pressure gauge, injector cleaning kit (if necessary)
• Connect the fuel pressure gauge to the fuel rail.
• Start the engine and check the fuel pressure against specifications (typically around 40-50 psi).
• If low, inspect the fuel filter and pump.
• If injectors are suspected to be clogged, use an injector cleaning kit to clean them or replace if necessary.

5. Inspect Air Intake and Vacuum Lines

• Visually inspect the air intake for blockages and ensure the air filter is clean.
• Inspect all vacuum lines for cracks or disconnections.
• Replace any damaged hoses and clean the throttle body if necessary.