how to fix P0420 code on 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, safety glasses, gloves.
• Disconnect the vehicle's battery to prevent electrical shorts.
• Allow the engine to cool before starting repairs.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use the socket set to remove the oxygen sensors from the exhaust manifold and catalytic converter.
  4. Install new oxygen sensors by reversing the removal process. Ensure they are tightened according to manufacturer specifications (usually around 30-40 Nm).
  5. Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove any heat shields or covers blocking access to the catalytic converter.
  2. Unbolt the catalytic converter from the exhaust system using the socket set.
  3. Inspect the catalytic converter for physical damage or signs of clogging.
  4. If damaged, install a new catalytic converter, ensuring all gaskets and seals are in good condition.
  5. Torque the bolts to the manufacturer's specifications (typically around 30-50 Nm).

4. Reconnect Battery and Clear Codes

• Reconnect the vehicle's battery.
• Use the OBD-II scanner to clear any existing error codes from the system.