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

Solution

1. Preparation

• Gather tools and parts needed.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before beginning any work.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket
• Remove the ignition coil from cylinder 1 by unbolting it and disconnecting the electrical connector.
• Use the spark plug socket to remove the spark plug from cylinder 1.
• Inspect the spark plug for signs of wear, carbon buildup, or damage. Replace if necessary.
• Install the new spark plug and torque it to the manufacturer’s specifications (typically around 13 ft-lbs).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Check and Replace Ignition Coil (if needed)

• If the spark plug is in good condition, test the ignition coil function by swapping it with a known good coil.
• Clear the P0301 code and run the engine to see if the misfire follows to the other cylinder.
• If it does, replace the faulty ignition coil with a new one. Torque the mounting bolts to manufacturer specifications.

4. Test Fuel Injector

• If misfire persists, inspect the fuel injector for cylinder 1.
• Tools Required: Noid light or multimeter
• Disconnect the fuel injector connector and test for voltage while cranking the engine.
• If there is no voltage, check for electrical issues; if there is voltage, consider replacing the fuel injector.

5. Compression Test

• If the misfire continues after checking the spark plug, ignition coil, and fuel injector, perform a compression test on cylinder 1.
• Tools Required: Compression gauge
• If compression is low, further diagnose for potential internal engine issues (valve problems, piston rings, etc.).