how to fix the P0420 code on my Tesla Model S Plaid/Refresh (2021-present)

Learn how to diagnose and fix P0420 code in Tesla Model S Plaid. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface, and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Unplug the electrical connectors from both sensors.
  3. Use the O2 sensor socket to remove the sensors from their respective locations.
  4. Install the new oxygen sensors and torque them to the manufacturer’s specifications (typically around 30-40 lb-ft).
  5. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust clamp tool.
• Steps:
  1. Remove the exhaust heat shield if applicable.
  2. Disconnect the exhaust pipes from the catalytic converter using the socket set.
  3. Remove any mounting bolts or clamps securing the catalytic converter.
  4. Install the new catalytic converter, ensuring proper alignment.
  5. Reconnect the exhaust pipes and torque the bolts to manufacturer specifications (typically around 30-50 lb-ft).
  6. Reinstall the heat shield if applicable.

4. Clear Codes and Test

• Tools Required: OBD-II scanner.
• Steps:
  1. Reconnect the negative battery terminal.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Start the vehicle and allow it to reach operating temperature.
  4. Perform a test drive to monitor for any check engine light illumination.