how to fix the P0301 misfire code in my Toyota Highlander Third Generation (2014-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Remove Ignition Coil and Spark Plug

• Tools Required: Ratchet and socket set, torque wrench.
• Remove the engine cover if necessary.
• Disconnect the electrical connector from the ignition coil.
• Remove the ignition coil bolt and gently pull the coil out.
• Use a spark plug socket to remove the spark plug from cylinder 1.

3. Inspect and Replace Components

• Check the spark plug for signs of wear or damage. Replace if necessary (use OEM specifications).
• Test the ignition coil using a multimeter; if out of range, replace with a new ignition coil.
• If the fuel injector was found faulty, replace it with a new one, ensuring to clean the intake manifold before installation.

4. Reassemble

• Install the new or inspected spark plug into cylinder 1 and torque to manufacturer specifications (typically around 13-15 ft-lbs).
• Reinstall the ignition coil and secure it with the bolt, reconnecting the electrical connector.
• If the engine cover was removed, reinstall it.

5. Final Checks

• Reconnect the negative battery terminal.
• Start the engine and allow it to reach operating temperature.