how to fix P0303 misfire code on my Toyota RAV4 XA40 (2013-2018)

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface with the parking brake engaged.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Gather all necessary tools and parts.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 3:
  1. Unscrew the bolts securing the ignition coil.
  2. Gently pull the ignition coil out of the spark plug well.
• Remove the spark plug:
  1. Use a spark plug socket and ratchet to unscrew the spark plug.
  2. Inspect the old spark plug for wear or damage.
• Install the new spark plug:
  1. Hand-tighten the new spark plug into the cylinder head.
  2. Use a torque wrench to tighten the spark plug to the manufacturer’s specification (typically around 13-15 lb-ft).
• Reinstall the ignition coil.

3. Check and Replace Ignition Coil (if necessary)

• If the ignition coil was suspected to be faulty:
  1. Disconnect the electrical connector from the ignition coil.
  2. Remove the ignition coil from the spark plug well.
  3. Install the new ignition coil by reversing the removal steps and ensuring it is seated properly.

4. Inspect/Replace Fuel Injector (if necessary)

• For fuel injector issues:
  1. Disconnect the fuel injector electrical connector.
  2. Remove the fuel rail bolts and lift the rail to access the injector.
  3. Remove the faulty injector from the rail.
  4. Install the new fuel injector and reassemble the fuel rail.

5. Final Assembly

• Reconnect the negative battery terminal.
• Clear the error codes using the OBD-II scanner.