what should I do if my Tesla Model S Plaid/Refresh (2021-present) shows P0420 error code?

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 necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to avoid electrical shorts.

2. Inspect and Clean Oxygen Sensors

• Tools Required: O2 sensor socket, multimeter
  • Remove the oxygen sensors from the exhaust system.
  • Clean the sensor connectors and inspect the wiring for damage.
  • Test the sensors with a multimeter to ensure they are within specifications (refer to service manual for specific values).
  • Replace any faulty oxygen sensors.

3. Inspect Catalytic Converter

• Tools Required: Socket set, torque wrench
  • Remove the catalytic converter from the exhaust system.
  • Visually inspect the catalyst for signs of melting, clogging, or physical damage.
  • If defective, replace with an OEM or high-quality aftermarket catalytic converter.
  • Reinstall the catalytic converter using the specified torque values.

4. Check for Exhaust Leaks

• Tools Required: Exhaust leak detector or smoke machine
  • Perform a smoke test or use an exhaust leak detector to identify any leaks in the exhaust system.
  • Repair or replace any damaged components as necessary.

5. Reassemble and Reconnect

• Reinstall oxygen sensors and secure all connections.
• Reconnect the negative battery terminal.
• Start the vehicle and allow it to reach operating temperature.