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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shock.
• Allow the engine to cool before beginning work.

2. Replace Spark Plug

• Tools Needed: Socket set, torque wrench, spark plug socket, gap gauge
  1. Remove the ignition coil for cylinder 1 by unscrewing the bolts and disconnecting the electrical connector.
  2. Remove the old spark plug using the spark plug socket and inspect it for signs of wear or fouling.
  3. Set the gap of the new spark plug to the manufacturer’s specifications (usually around 0.044 inches).
  4. Install the new spark plug, torque to specified value (typically 13 lb-ft).
  5. Reinstall the ignition coil and reconnect the electrical connector.

3. Replace Ignition Coil (if necessary)

• Tools Needed: Socket set
  1. If the ignition coil was found faulty during diagnostics, remove it by unscrewing the mounting bolts.
  2. Install the new ignition coil in place, ensuring it is seated properly.
  3. Reconnect the electrical connector and any other components that were removed.

4. Inspect and Clean Fuel Injector

• Tools Needed: Fuel injector cleaning kit (if needed)
  1. Disconnect the fuel injector connector for cylinder 1.
  2. Remove the fuel rail if necessary to access the injector.
  3. Inspect the injector for clogs and clean it using a fuel injector cleaner if needed.
  4. Reinstall the fuel injector and reconnect the wiring harness.

5. Perform Compression Test (if necessary)

• Tools Needed: Compression tester
  1. Remove the spark plug from cylinder 1 and insert the compression tester.
  2. Crank the engine and observe the compression reading. It should match manufacturer specifications (typically around 180 psi).
  3. If the compression is low, further investigation may be needed for potential internal engine issues.