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 tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Unplug the electrical connectors from the oxygen sensors.
  3. Using the O2 sensor socket, remove the oxygen sensors from their respective locations.
  4. Install the new oxygen sensors and tighten them to the manufacturer's specified torque (typically around 30 lb-ft).
  5. Reconnect the electrical connectors to the oxygen sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack and jack stands, torque wrench
• Sub-steps:
  1. Raise the vehicle using a jack and secure it with jack stands.
  2. Disconnect the exhaust pipes leading to and from the catalytic converter.
  3. Remove any mounting bolts or brackets holding the catalytic converter in place.
  4. Carefully remove the catalytic converter from the exhaust system.
  5. Install the new catalytic converter in the reverse order of removal, ensuring all bolts are torqued to the manufacturer’s specifications.

4. Check for Exhaust Leaks

• Tools Required: Exhaust leak detection kit or soapy water
• Sub-steps:
  1. Start the vehicle and let it idle.
  2. Use the exhaust leak detection kit or spray soapy water around the exhaust joints and connections.
  3. Look for bubbles forming, indicating a leak. If found, repair or replace the leaking sections.

5. Reset the ECU

• Tools Required: OBD-II scanner
• Sub-steps:
  1. Use the OBD-II scanner to clear the P0420 code from the vehicle's ECU.
  2. Reconnect the negative battery terminal.