how to fix the P0301 misfire code in my Toyota RAV4 XA50 (2019-2024)?

Solution

1. Preparation

• Gather tools and parts needed.
• Ensure the engine is cool and disconnect the negative battery terminal.

2. Replace Spark Plug

• Remove engine cover (if applicable): Use a socket set to unscrew any bolts holding the cover.
• Remove spark plug:
  • Use a spark plug socket and ratchet to unscrew the spark plug from cylinder 1.
  • Check the gap on the new spark plug and ensure it meets specifications (typically around 0.043 inches for most Toyota engines).
• Install new spark plug:
  • Insert the new spark plug and tighten to approximately 13 lb-ft using a torque wrench.

3. Inspect and Replace Ignition Coil

• Remove ignition coil:
  • Disconnect the electrical connector from the ignition coil.
  • Unbolt the ignition coil from the cylinder head (usually 10 mm socket).
• Test ignition coil:
  • Use a multimeter to measure resistance; refer to the specifications in the service manual.
• Install new ignition coil:
  • If the ignition coil is faulty, replace it with a new one, reattach the connector, and bolt it back securely.

4. Check and Test Fuel Injector

• Test fuel injector:
  • Disconnect the injector connector and use a multimeter to check for resistance (usually around 12-16 ohms).
• Replace injector:
  • If faulty, remove the fuel rail (may require depressurizing the fuel system first).
  • Replace the fuel injector in cylinder 1 and ensure it is seated properly.

5. Reassemble and Final Checks

• Reinstall components: Reattach any covers and reconnect the battery terminal.
• Clear codes: Use an OBD-II scanner to clear the P0301 code and reset the engine light.