how to fix P0301 code in my Toyota Highlander Fourth Generation (2020-present)

Solution

1. Preparation

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

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coil and spark plug from cylinder 1.
• Inspect the spark plug for damage or excessive wear. Replace if necessary.
• Torque the new spark plug to the manufacturer’s specification (typically around 13-15 lb-ft).
• Reinstall the ignition coil ensuring it properly seats.

3. Inspect and Replace Ignition Coil

• Tools Required: Socket set, multimeter (if testing).
• Remove the ignition coil from cylinder 1.
• Inspect the ignition coil for cracks or signs of wear.
• Test the resistance of the coil using a multimeter; replace it if it falls outside manufacturer specifications.
• Install the new ignition coil, ensuring all connectors are secure.

4. Clean or Replace Fuel Injector

• Tools Required: Fuel injector cleaning kit or replacement injector.
• Remove the fuel injector from cylinder 1 using the appropriate tools.
• If cleaning, follow the cleaning kit instructions to ensure the injector is unclogged.
• If replacing, install the new fuel injector and ensure it is securely fastened.

5. Reassemble and Reconnect

• Reinstall any components removed during the process, ensuring all connections are secure.
• Reconnect the negative battery terminal.