how to fix P0301 cylinder 1 misfire in Toyota Highlander Third Generation (2014-2019)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Replace Spark Plug

• Sub-steps:
  • Remove the engine cover if applicable using a socket set.
  • Disconnect the ignition coil connector from the ignition coil for cylinder 1.
  • Remove the ignition coil using a socket wrench.
  • Remove the spark plug using a spark plug socket and ratchet.
  • Install a new spark plug, ensuring it is properly gapped according to manufacturer specifications (typically 0.043 inches).
  • Reinstall the ignition coil and connector.

3. Replace Ignition Coil (if necessary)

• Sub-steps:
  • If the ignition coil was found faulty during inspection, replace it.
  • Remove the old ignition coil and install the new one, ensuring it is seated correctly.
  • Reconnect the ignition coil connector.

4. Replace Fuel Injector (if necessary)

• Sub-steps:
  • If the fuel injector was found faulty, disconnect the fuel line and electrical connector.
  • Remove the fuel injector from the fuel rail.
  • Install a new fuel injector, ensuring proper orientation and sealing.
  • Reconnect the fuel line and electrical connector.

5. Final Steps

• Reconnect the negative battery terminal.
• Start the engine and let it idle. Check for any leaks or abnormal noises.