how to diagnose P0301 misfire code on Toyota Tacoma N300 (2016-Present)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is on a flat surface and securely supported.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1 by unbolting it and disconnecting the electrical connector.
• Remove the spark plug using a spark plug socket and ratchet.
  • Tools Required: Spark plug socket, ratchet wrench, torque wrench.
• Inspect the spark plug for wear or fouling; replace if necessary with a spark plug that meets OEM specifications.
• Reinstall the spark plug and torque to the manufacturer’s specifications (typically around 13-16 ft-lbs).

3. Inspect and Replace Ignition Coil

• If the spark plug is in good condition, test the ignition coil for proper operation (if faulty, replace it).
• Reconnect the ignition coil and ensure it is seated properly.

4. Inspect and Clean Fuel Injector

• If the ignition system is functioning properly, remove the fuel injector for cylinder 1.
  • Disconnect the fuel line (use caution for fuel spills).
  • Remove the retaining clips and pull out the fuel injector.
• Clean the injector using a fuel system cleaner or replace it if clogged or damaged.
• Reinstall the injector, ensuring it is properly seated and secured with retaining clips.

5. Address Additional Issues

• If the issue persists after addressing the spark plug, ignition coil, and fuel injector, check the engine's compression and vacuum systems as indicated in the diagnostic steps.
• Repair any leaks in vacuum hoses and ensure all components are functioning correctly.