how to fix the P0303 misfire code in my Toyota RAV4 XA50 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on the electrical components.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if necessary.
  2. Disconnect the ignition coil connector from the spark plug.
  3. Remove the ignition coil from cylinder 3.
  4. Unscrew and remove the spark plug using a spark plug socket.
  5. Inspect the spark plug for wear or fouling; replace if necessary.
  6. Install the new spark plug and torque to manufacturer specifications (typically 13-16 lb-ft).
  7. Reinstall the ignition coil and reconnect the connector.

3. Check and Replace Ignition Coil

• Sub-steps:
  1. If the spark plug was fine, test the ignition coil using a multimeter to ensure it's functioning properly.
  2. If faulty, remove the ignition coil from cylinder 3.
  3. Install the new ignition coil and reconnect the electrical connector.
  4. Reinstall any engine covers removed during the process.

4. Inspect and Replace Fuel Injector

• Sub-steps:
  1. If misfire persists, remove the fuel injector from cylinder 3.
  2. Test the injector for proper operation using a fuel injector tester.
  3. Clean or replace the fuel injector as necessary.
  4. Reinstall the injector and ensure all connections are secure.

5. Compression Test

• Sub-steps:
  1. If issues persist, perform a compression test on cylinder 3.
  2. Remove the spark plug and install the compression tester.
  3. Crank the engine and record the compression reading.
  4. If the compression is low, further investigation into the engine’s internal components may be required.