how to fix 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 engage the parking brake.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: Oxygen sensor socket, wrench
• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Remove the electrical connectors from the oxygen sensors.
  3. Use the oxygen sensor socket to unscrew the sensors from the exhaust system.
  4. Install the new oxygen sensors by reversing the removal process. Ensure they are tightened to the manufacturer's specifications (typically around 30 lb-ft).
  5. Reconnect the electrical connectors.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, exhaust pipe cutter, gasket scraper
• Sub-steps:
  1. Remove any heat shields or protective covers from the catalytic converter.
  2. Cut the exhaust pipe using an exhaust pipe cutter to remove the old catalytic converter.
  3. Clean the exhaust flanges using a gasket scraper to ensure a proper seal.
  4. Install the new catalytic converter by aligning it with the exhaust flanges and securing it with bolts, tightening to the manufacturer's specifications (consult the service manual for torque values).
  5. Reinstall heat shields or protective covers.

4. Clear Error Codes

• Tools Required: OBD-II scanner
• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Start the engine and let it idle for a few minutes.
  3. Use the OBD-II scanner to clear the P0420 code from the system.