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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to avoid electrical shocks.
• Ensure the engine is cool before beginning work.

2. Inspect and Replace Spark Plug

1. Remove the ignition coil from cylinder 1:
   • Use a socket set to remove bolts securing the coil.
   • Carefully pull the coil out of the spark plug hole.
2. Remove the spark plug:
   • Use a spark plug socket to unscrew the spark plug from cylinder 1.
   • Inspect the spark plug for damage or excessive wear.
3. Install a new spark plug:
   • Set the gap according to manufacturer specifications (typically around 0.043 inches).
   • Install the new spark plug and torque it to manufacturer specifications (usually around 13 lb-ft).
4. Reinstall the ignition coil.

3. Inspect and Replace Ignition Coil (if necessary)

1. If the ignition coil shows signs of damage:
   • Remove the faulty ignition coil.
   • Install a new ignition coil, ensuring it clicks into place securely.
   • Reconnect the wiring harness.

4. Fuel Injector Check and Cleaning

1. If misfire persists, check the fuel injector for cylinder 1:
   • Remove the fuel rail if needed to access the injector.
   • Clean the injector using a fuel injector cleaning kit or replace it if necessary.
2. Reassemble any components removed during the process.

5. Clear Codes and Test

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0301 code.
3. Start the engine and allow it to reach operating temperature.