how to troubleshoot P0301 misfire code in Toyota Tacoma N300 (2016-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the battery to prevent electrical shock.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1 by unfastening the mounting bolts and disconnecting the electrical connector.
• Extract the spark plug using a spark plug socket. Inspect for wear, carbon buildup, or damage.
• If necessary, replace with a new spark plug (OEM specifications: NGK or Denso recommended).
• Reinstall the spark plug, ensuring proper torque (typically 13 lb-ft).

3. Check and Replace Ignition Coil

• Inspect the ignition coil for signs of damage or corrosion.
• If faulty, remove the ignition coil and replace it with a new one (ensure it matches OEM specifications).
• Reconnect the electrical connector and secure it in place.

4. Inspect and Clean Fuel Injector

• Remove the fuel injector from cylinder 1, ensuring to relieve fuel pressure beforehand.
• Inspect for clogs or carbon buildup. Clean the injector using a specialized cleaner if necessary.
• If the injector is faulty, replace it with a new one that meets OEM specifications.

5. Conduct Compression Test

• Install a compression gauge into the spark plug hole of cylinder 1.
• Crank the engine and record the compression reading. Compare it to the manufacturer’s specifications (typically around 180 psi).
• If compression is low, further investigation into the cylinder head, valves, or piston rings may be required.

6. Check for Vacuum Leaks

• Start the engine and use a smoke machine or carb cleaner to check for vacuum leaks around the intake manifold and vacuum hoses.
• Repair any identified leaks to restore proper engine operation.