how to fix P0303 misfire code in 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 the engine to cool before working on components.

2. Inspect and Replace Spark Plug

• Remove the ignition coil and spark plug from cylinder three.
• Inspect the spark plug for fouling, wear, or damage.
• Replace with a new spark plug if necessary, ensuring it meets OEM specifications (typically NGK or Denso).
• Torque the spark plug to the manufacturer's specification (usually around 13 lb-ft).

3. Inspect and Replace Ignition Coil

• If the spark plug is in good condition, test the ignition coil for proper resistance using a multimeter.
• If faulty, remove the ignition coil and install a new one that meets OEM specifications.
• Reinstall the ignition coil and ensure it is securely connected to the spark plug.

4. Check and Replace Fuel Injector (if necessary)

• Remove the fuel rail to access the fuel injector for cylinder three.
• Test the injector resistance with a multimeter; it should typically be around 12-16 ohms.
• If faulty, replace the injector with a new one that meets OEM specifications.
• Reinstall the fuel rail ensuring all seals are properly seated.

5. Reassemble and Reconnect

• Reconnect all components in reverse order of removal.
• Reconnect the negative battery terminal.
• Clear any diagnostic trouble codes using an OBD-II scanner.