how to fix P0420 code on 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

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, exhaust leak detector.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to ensure safety while working on electrical components.

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 from both sensors.
  3. Use a socket wrench to remove the sensors from the exhaust system.
  4. Install new oxygen sensors using anti-seize compound on the threads.
  5. Torque the sensors to the manufacturer’s specifications (typically around 30 lb-ft).
  6. Reconnect the electrical connectors for both sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Visually inspect the catalytic converter for any signs of damage or excessive heat.
  2. If replacement is necessary, disconnect the exhaust pipes leading to and from the catalytic converter.
  3. Remove the bolts securing the catalytic converter to the exhaust system using a socket set.
  4. Install the new catalytic converter, ensuring proper alignment.
  5. Torque all bolts to the manufacturer’s specifications.
  6. Reconnect the exhaust pipes securely.

4. Clear Codes and Test

• Sub-steps:
  1. Reconnect the vehicle’s 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.
  4. Monitor the live data from the O2 sensors again to ensure they are functioning correctly.