how to fix P0420 code in my Toyota Corolla E210 (2019-2024)

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, exhaust backpressure gauge.
• Safety Warnings: Ensure the engine is cool before beginning work. Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Disconnect the electrical connectors for both oxygen sensors.
  3. Use a wrench to remove the sensors from their respective locations.
  4. Install new oxygen sensors and tighten them to the manufacturer's specified torque (usually around 30 lb-ft).
  5. Reconnect the electrical connectors.

3. Examine and Replace the Catalytic Converter

• Sub-steps:
  1. Raise the vehicle securely on jack stands.
  2. Locate the catalytic converter in the exhaust system.
  3. Use a socket set to remove the bolts securing the catalytic converter to the exhaust pipes.
  4. Carefully remove the catalytic converter from the exhaust system.
  5. Install the new catalytic converter, ensuring proper alignment and sealing.
  6. Torque the bolts to the specified value (typically around 30 lb-ft).

4. Clear the Error Code

• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code from the vehicle's memory.
  3. Start the vehicle and allow it to reach operating temperature.