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

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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the vehicle to cool down before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  • Locate the pre-catalytic converter and post-catalytic converter oxygen sensors.
  • Disconnect the electrical connectors from both sensors.
  • Use a wrench to remove the sensors from the exhaust system.
  • Install new oxygen sensors (ensure they are compatible with the Tesla Model S).
  • Reconnect the electrical connectors securely.
• Tools Required: Oxygen sensor socket, wrench set, multimeter.

3. Examine and Replace Catalytic Converter

• Sub-steps:
  • Remove any heat shields or covers obstructing access to the catalytic converter.
  • Disconnect the exhaust pipes connected to the catalytic converter using a wrench.
  • Remove the catalytic converter from its mounting points.
  • Install the new catalytic converter, ensuring proper alignment and fit.
  • Reconnect the exhaust pipes and secure with appropriate hardware.
  • Reinstall heat shields or covers if removed.
• Tools Required: Socket set, torque wrench, exhaust pipe clamps.

4. Reset the ECU

• Sub-steps:
  • Reconnect the negative battery terminal.
  • Use an OBD-II scanner to clear the P0420 code from the ECU.
  • Start the engine and allow it to reach operating temperature to ensure proper functionality.
• Tools Required: OBD-II scanner.