how to fix the P0420 code on my Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and secured with wheel chocks.
• Disconnect the battery to prevent any electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
  • 1. Locate the upstream and downstream oxygen sensors on the exhaust pipe.
  • 1. Disconnect the electrical connectors from both sensors.
  • 1. Use the O2 sensor socket to carefully remove the sensors.
  • 1. Install the new sensors by threading them in by hand and then tightening to the manufacturer’s specified torque (typically 30 lb-ft).
  • 1. Reconnect the electrical connectors.

3. Examine and Replace Catalytic Converter

• Tools Required: Socket set, exhaust hanger removal tool, torque wrench
  • 1. Remove any heat shields or components obstructing access to the catalytic converter.
  • 1. Use the socket set to unbolt the catalytic converter from the exhaust manifold and the exhaust pipe.
  • 1. Carefully lower the catalytic converter and inspect for damage.
  • 1. Install the new catalytic converter, ensuring proper alignment.
  • 1. Torque the bolts to the manufacturer’s specifications, ensuring a secure fit.
  • 1. Reinstall any heat shields or components removed during the process.

4. Clear Codes and Test

• Tools Required: OBD-II scanner
  • 1. Reconnect the battery.
  • 1. Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
  • 1. Start the engine and allow it to reach operating temperature.
  • 1. Take the vehicle for a test drive to ensure the check engine light does not reappear.