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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before proceeding.

2. Inspect and Replace Spark Plug

• Remove the ignition coil cover if applicable.
• Disconnect the ignition coil connector from cylinder 1.
• Remove the ignition coil using a socket set.
• Inspect the spark plug for wear or damage; replace if necessary.
• Install a new spark plug (Torque to 13 lb-ft).
• Reinstall the ignition coil and reconnect the connector.

3. Test and Replace Ignition Coil (if necessary)

• If the ignition coil appears damaged or does not test properly, replace it.
• Remove the faulty ignition coil and install a new one.
• Ensure the connector is securely attached.

4. Check Fuel Injector

• Using a multimeter, check the resistance of the fuel injector for cylinder 1 (should be within manufacturer specs).
• If faulty, remove the fuel injector from cylinder 1.
• Replace with a new fuel injector ensuring proper seating and connection.

5. Compression Test

• Perform a compression test on cylinder 1.
• If the compression is below the manufacturer's specification, further investigation of internal engine components may be required.