how to fix the P0301 code on my Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression gauge, multimeter, fuel injector cleaner
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Replace Ignition Coil (if faulty)

• Remove the engine cover (if present) using a socket set.
• Disconnect the ignition wire and the electrical connector from the ignition coil in cylinder 1.
• Remove the bolts securing the ignition coil using a socket.
• Install the new ignition coil by reversing the removal steps, ensuring it is seated correctly. Torque the bolts to the manufacturer’s specification.

3. Replace Spark Plug (if faulty)

• Remove the ignition coil (as detailed in Step 2).
• Use a spark plug socket to remove the spark plug from cylinder 1.
• Inspect the spark plug for wear or carbon buildup. If necessary, replace it with a new one.
• Gap the new spark plug to the manufacturer’s specifications before installation.
• Install the new spark plug and torque it to the specified value.

4. Clean or Replace Fuel Injector (if necessary)

• If the injector is suspected of malfunctioning, remove it by disconnecting the fuel line and electrical connector.
• Use a fuel injector cleaner to clean the injector or replace it if cleaning does not resolve the issue.
• Reinstall the injector securely and reconnect the fuel line and electrical connector.

5. Reassemble and Test

• Reconnect the negative battery terminal.
• Clear the trouble codes using the OBD-II scanner.
• Start the engine and allow it to reach operating temperature.