my Toyota Highlander has code P0301 what does it mean and how to fix it

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery (negative terminal) to ensure safety.

2. Inspect Ignition Components

• Remove the engine cover if applicable.
• Disconnect the ignition coil connector from cylinder 1.
• Remove the ignition coil by unscrewing the retaining bolts.
• Check the spark plug condition; replace if worn or fouled.
• Install a new spark plug (torque to manufacturer specifications).

3. Clean or Replace Fuel Injector

• Remove the fuel rail if necessary to access the fuel injector for cylinder 1.
• Disconnect the fuel injector connector.
• Remove the fuel injector from the rail.
• Clean the injector using a fuel injector cleaner or replace it if faulty.
• Reinstall the injector and reconnect the fuel line and connector.

4. Perform Compression Test

• Remove the spark plug from cylinder 1.
• Insert the compression tester into the spark plug hole.
• Crank the engine and record the compression reading; compare to manufacturer's specifications.
• If compression is low, further investigation into valve or piston condition may be necessary.

5. Reassemble and Reconnect

• Reattach any components that were removed for access.
• Reconnect the ignition coil and any electrical connectors.
• Reconnect the battery terminal.