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 vehicle's 12V battery to prevent electric shock and ensure safety.
• Ensure the vehicle is parked on a flat surface and use wheel chocks.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, OBD-II scanner.
• Remove the O2 sensor from the exhaust manifold and inspect it for damage.
  • If faulty, install a new oxygen sensor:
    1. Apply anti-seize compound to the threads of the new O2 sensor.
    2. Install the new sensor and torque it to the manufacturer's specification (typically around 30 lb-ft).
    3. Reconnect the electrical connector.

3. Inspect Catalytic Converter

• Tools Required: Jack, jack stands, exhaust system inspection mirror.
• Visually inspect the catalytic converter for any signs of physical damage (cracks, dents, etc.).
• If damaged, replace the catalytic converter:
  1. Remove any bolts or clamps securing the catalytic converter.
  2. Carefully lower the converter from the exhaust system.
  3. Install the new catalytic converter and ensure all connections are secure.
  4. Torque bolts to manufacturer specifications.

4. Clear Error Codes

• Use the OBD-II scanner to clear the P0420 code after repairs are made.
• Reconnect the vehicle's battery.

5. Test Drive

• Conduct a test drive to ensure the check engine light does not reappear and the vehicle operates normally.