how to fix P0303 misfire code in my Toyota RAV4 Fourth Generation (2013-2018)?

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal for safety.
• Allow the engine to cool down before proceeding.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 3.
• Use a spark plug socket to carefully unscrew and remove the spark plug.
• Inspect the spark plug for signs of wear or damage (e.g., fouling, cracks).
• Install a new spark plug (use OEM specifications, typically NGK or Denso).
• Torque the spark plug to manufacturer specifications (usually around 13 lb-ft).

3. Test or Replace Ignition Coil

• Remove the ignition coil from cylinder 3.
• Test the ignition coil using a multimeter (primary and secondary resistance).
  • If faulty, replace it with a new ignition coil.
• Reinstall the new or tested ignition coil securely.

4. Inspect and Clean Fuel Injector

• Remove the fuel rail if necessary to access the injector for cylinder 3.
• Inspect the fuel injector for clogs or leaks.
• Clean the injector using an appropriate fuel injector cleaner or replace it if necessary.
• Reinstall the injector and ensure all connections are secure.

5. Repair Vacuum Leaks (if found)

• Inspect and replace any damaged vacuum hoses or gaskets around the intake manifold.
• Ensure all connections are tight to prevent air leaks.