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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, jack and jack stands.
• Ensure the vehicle is on a level surface and the engine is cool.
• Disconnect the battery to prevent any electrical issues.

2. Inspect and Replace O2 Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) O2 sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use a socket to remove the O2 sensors from their respective locations.
  4. Install new O2 sensors, tightening them to the manufacturer's torque specifications (typically around 30 Nm).
  5. Reconnect the electrical connectors.

3. Inspect the Catalytic Converter

• Sub-steps:
  1. Check for physical damage, such as dents or holes in the catalytic converter housing.
  2. If damaged, remove and replace the catalytic converter:
     • Use a socket set to loosen the bolts connecting the catalytic converter to the exhaust system.
     • Remove the catalytic converter and replace it with a new unit, ensuring proper fitment.
     • Tighten the bolts to manufacturer specifications.

4. Clear the Error Codes

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