how to fix P0420 code in my 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 required tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to avoid electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  • Locate the upstream and downstream oxygen sensors in the exhaust system.
  • Unplug the electrical connectors from each sensor.
  • Remove the sensors using an oxygen sensor socket.
  • Install new oxygen sensors, tightening to the manufacturer's torque specifications (typically around 30 ft-lbs).
  • Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if needed)

• Sub-steps:
  • Remove the exhaust heat shield if present to access the catalytic converter.
  • Disconnect the exhaust pipes from both ends of the catalytic converter.
  • Remove any mounting bolts or clamps securing the catalytic converter.
  • Install a new catalytic converter, ensuring proper gasket alignment.
  • Reconnect the exhaust system and tighten all bolts to the manufacturer's specifications.

4. Clear Codes and Test Drive

• Sub-steps:
  • Reconnect the battery.
  • Use the OBD-II scanner to clear the P0420 code.
  • Start the vehicle and allow it to reach operating temperature.
  • Perform a test drive to ensure the check engine light does not reappear and that the vehicle operates normally.