how to troubleshoot misfires in my Toyota Tacoma N300 (2016-Present) with P0301 code

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to avoid electrical shock.

2. Inspect and Replace Ignition Coil

• Tools Required: Socket set, torque wrench, multimeter
• Remove the engine cover if applicable.
• Locate the ignition coil for cylinder 1 (refer to the service manual for location).
• Disconnect the electrical connector from the ignition coil.
• Remove the bolts securing the ignition coil and lift it out.
• Sub-steps:
  • Test the ignition coil with a multimeter to ensure it has proper resistance.
  • If faulty, replace with a new ignition coil, ensuring it is seated properly and bolts are torqued to specification (typically around 7-10 ft-lbs).

3. Inspect and Replace Spark Plug

• Remove the spark plug from cylinder 1 using a spark plug socket.
• Inspect the spark plug for signs of wear, carbon buildup, or oil contamination.
• Sub-steps:
  • If the spark plug is worn or fouled, replace it with a new one, ensuring it is gapped to the manufacturer specification (usually around 0.043 inches).
  • Reinstall the spark plug and torque it to the recommended value (typically around 13-16 ft-lbs).

4. Test and Clean Fuel Injector

• Locate the fuel injector for cylinder 1 and disconnect the electrical connector.
• Use a fuel injector tester or a multimeter to check for proper resistance.
• Sub-steps:
  • If the injector is faulty, replace it with a new one.
  • If it is operational, clean the injector using a fuel injector cleaning kit or replace the fuel filter if clogged.

5. Perform Compression Test

• Remove the spark plug from cylinder 1 to allow access for the compression tester.
• Insert the compression tester into the spark plug hole.
• Sub-steps:
  • Crank the engine to get a reading and ensure it meets manufacturer specifications (typically around 150 psi).
  • If compression is low, further investigation into internal engine issues may be required.