how to solve the P0420 error code in my Toyota Corolla E170 (2013-2019)?

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, multimeter, jack and jack stands.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Remove the sensors using a socket or wrench.
  4. Install new oxygen sensors by reversing the removal steps. Ensure they are torqued to manufacturer specifications (typically around 30 ft-lbs).
  5. Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Inspect the catalytic converter for any signs of damage or blockage.
  2. If damaged, remove the exhaust pipe leading to the catalytic converter using a socket set.
  3. Remove the catalytic converter from its mounting brackets.
  4. Install the new catalytic converter, ensuring proper alignment and sealing.
  5. Reattach the exhaust pipe and secure with bolts to the manufacturer’s torque specifications.

4. Clear Error Codes

• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 error code.
  3. Start the engine and allow it to reach normal operating temperature.