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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to avoid electrical shorts.
• Ensure the engine is cool before starting repairs.

2. Inspect and Replace Ignition Components

• Tools Required: Socket set, torque wrench, spark plug socket
• Remove the engine cover if applicable.
• Disconnect the ignition coil connector on cylinder 1.
• Remove the ignition coil using a socket set.
• Remove the spark plug with a spark plug socket and inspect for wear or carbon buildup.
• Replace the spark plug with a new one (use OEM parts, typically NGK or Denso).
• Reinstall the ignition coil, ensuring it is properly seated and connected.
• Torque specifications for spark plugs: Approximately 13 lb-ft (17 Nm).

3. Check and Replace Fuel Injector

• Tools Required: Fuel injector removal tool, O-ring lubricant
• Disconnect the fuel injector connector for cylinder 1.
• Remove the fuel rail if necessary to access the injector.
• Carefully pull out the fuel injector from its seat.
• Inspect the injector for clogs or damage; replace if necessary (ensure O-rings are lubricated before installation).
• Reinstall the fuel injector and reconnect the fuel rail, ensuring all seals are secure.

4. Perform a Compression Test

• Tools Required: Compression gauge
• Remove the spark plug for cylinder 1.
• Insert the compression gauge into the spark plug hole.
• Crank the engine for a few seconds and record the reading.
• Compare the compression reading to the manufacturer's specifications (typically around 180 psi).
• If the compression is low, further investigation into the engine's mechanical integrity is needed.