how to fix the P0301 misfire code on Toyota RAV4 XA50 (2019-2024)

Solution

1. Preparation

• Gather tools and parts:
  • Tools: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, spark plug socket.
  • Parts: New spark plug, ignition coil (if necessary), fuel injector cleaner (optional).
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Disconnect the negative battery terminal to prevent electrical shorts.
  2. Remove the ignition coil from cylinder 1 by unscrewing the mounting bolts.
  3. Take out the spark plug using the spark plug socket.
  4. Inspect the spark plug for damage or excessive wear; replace if necessary.
  5. Install the new spark plug, hand-tighten, then torque to manufacturer specifications (typically around 13-15 lb-ft).

3. Test and Replace Ignition Coil (if necessary)

• Sub-steps:
  1. Reconnect the ignition coil connector.
  2. Use a multimeter to check the resistance of the ignition coil; consult the service manual for specifications.
  3. If the coil is faulty, remove it again and replace it with a new one.
  4. Reinstall the ignition coil and ensure all connections are secure.

4. Compression Test (if misfire persists)

• Sub-steps:
  1. Remove the spark plug from cylinder 1 again.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine and record the compression reading.
  4. Compare the reading to the manufacturer specifications; if low, further investigation is needed.

5. Clean Fuel Injectors (if applicable)

• Sub-steps:
  1. Use fuel injector cleaner as per the instructions in the product manual.
  2. If injectors are suspected to be clogged, consider professional cleaning or replacement.