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

Solution

1. Preparation

• Gather tools and parts required.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative terminal of the battery to prevent electrical shorts.

2. Inspect and Replace Spark Plug

1. Remove the engine cover if applicable.
2. Locate cylinder 1 spark plug (usually near the front of the engine).
3. Use a socket wrench to remove the spark plug.
4. Inspect the spark plug for wear, carbon buildup, or damage.
5. If necessary, replace with a new spark plug that meets OEM specifications.
   • Torque the new spark plug to manufacturer’s specification (typically around 13-15 lb-ft).

3. Check and Replace Ignition Coil

1. Disconnect the electrical connector from the ignition coil on cylinder 1.
2. Remove the ignition coil by unscrewing any retaining bolts.
3. Inspect the coil for cracks or signs of damage.
4. If faulty, install a new ignition coil and secure it with bolts.
5. Reconnect the electrical connector.

4. Inspect and Clean Fuel Injector

1. Locate the fuel injector for cylinder 1.
2. Disconnect the fuel injector electrical connector.
3. Use a fuel line disconnect tool to remove the fuel line, taking precautions to catch any spilled fuel.
4. Remove the fuel injector and inspect for dirt or blockage.
5. Clean the injector using a cleaning kit or replace it if necessary.
6. Reinstall the injector and reconnect the fuel line and electrical connector.

5. Compression Test

1. Remove the spark plug from cylinder 1 again.
2. Insert a compression gauge into the spark plug hole.
3. Crank the engine and note the compression reading; it should meet manufacturer's specifications (generally around 150-200 psi).
4. If compression is low, further investigation may be needed for potential head gasket or valve issues.