how to fix P0303 misfire code in Toyota RAV4 XA40 (2013-2018)?

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to ensure safety during the repair process.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 3:
  • Unscrew the ignition coil bolts with a socket set.
  • Gently pull the coil out of the spark plug well.
• Remove the spark plug:
  • Use a spark plug socket to unscrew the spark plug from cylinder 3.
  • Inspect the spark plug for wear or damage.
• Install a new spark plug:
  • Ensure the gap is set according to manufacturer specifications (typically around 0.043 inches for Toyota).
  • Apply anti-seize compound on the threads if recommended, then install the new spark plug and torque it to 13 lb-ft.

3. Inspect and Replace Ignition Coil

• Inspect the ignition coil for physical damage or signs of arcing.
• If necessary, replace the ignition coil:
  • Install the new ignition coil onto the spark plug and secure it with bolts.
  • Reconnect the electrical connector to the ignition coil.

4. Check and Clean Fuel Injector

• Remove the fuel injector for cylinder 3:
  • Disconnect the fuel line (use caution as fuel may spill).
  • Unclip the injector wiring harness.
  • Remove the retaining clips and pull the injector out.
• Clean the injector with a dedicated fuel injector cleaner or replace it if faulty.
• Reinstall the injector and reconnect the wiring harness.

5. Reassemble and Final Checks

• Reconnect the battery.
• Start the engine and allow it to reach operating temperature.
• Clear the trouble codes using an OBD-II scanner.