how to fix P0301 code in Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

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

2. Replace Spark Plug and Ignition Coil for Cylinder 1

• Tools Required: Socket set, torque wrench, spark plug socket, ratchet.
• Remove the engine cover if applicable.
• Locate the ignition coil for cylinder 1 (refer to the vehicle’s service manual for location).
• Disconnect the electrical connector from the ignition coil.
• Remove the ignition coil mounting bolts and gently pull out the coil.
• Remove the spark plug using the spark plug socket. Inspect for wear or damage.
• Install a new spark plug, torquing it to the manufacturer’s specification (typically around 13-15 lb-ft).
• Insert the new ignition coil, securing it with bolts and reconnecting the electrical connector.

3. Inspect and Clean Fuel Injector

• Tools Required: Fuel injector cleaner, safety goggles, and gloves.
• Access the fuel injector for cylinder 1 (may require manifold removal).
• Disconnect the fuel injector electrical connector.
• Use an appropriate tool to remove the fuel injector.
• Clean the injector with a fuel injector cleaner or replace it if faulty.
• Reinstall the injector, ensuring it is seated properly and reconnect the electrical connector.

4. Perform Compression Test

• Tools Required: Compression tester.
• Remove the spark plug for cylinder 1.
• Install the compression tester and crank the engine to obtain the reading.
• Compare the reading to the specifications in the service manual; a low reading indicates potential internal engine issues.

5. Repair Vacuum Leaks

• Tools Required: Smoke machine or carburetor cleaner.
• Inspect the intake manifold and vacuum hoses for leaks.
• Use a smoke machine or spray carburetor cleaner around suspected areas and watch for changes in engine RPM.
• Replace any damaged hoses or gaskets.