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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.

2. Replace Spark Plug and Ignition Coil

• Tools Required: Socket set, torque wrench
• Remove the engine cover (if applicable) by unscrewing bolts or clips.
• Disconnect the ignition coil connector and remove the ignition coil from cylinder 1 by unscrewing it.
• Remove the spark plug from cylinder 1 using a spark plug socket.
• Inspect the old spark plug for wear; if it shows signs of wear or fouling, replace it with a new one.
• Install the new spark plug by hand, then torque to manufacturer specifications (typically 13-15 ft-lbs).
• Install the new ignition coil and reconnect the connector.

3. Inspect and Replace Fuel Injector (if necessary)

• Tools Required: Fuel injector removal tool, O-rings (if needed)
• Relieve fuel system pressure by removing the fuel pump fuse and cranking the engine for a few seconds.
• Disconnect the fuel line from the injector and remove the retaining clips.
• Carefully pull out the fuel injector from the rail.
• Inspect the injector for clogs or damage; replace if necessary with a new fuel injector.
• Reinstall the injector and reconnect the fuel line with new O-rings if required.

4. Conduct Compression Test

• Tools Required: Compression tester
• Remove the spark plug from cylinder 1 again.
• Insert the compression tester into the spark plug hole and crank the engine.
• Observe the reading; it should be within the manufacturer's specified range (typically around 180-200 psi).
• If the compression is low, further diagnostics may be necessary to check for valve or head gasket issues.