how to troubleshoot P0420 code on my Tesla Model S Plaid/Refresh

Learn how to troubleshoot and fix P0420 exhaust system issue in Tesla Model S Plaid. Step-by-step guide with diagnostic and repair instructions.

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface and the ignition is off.
• Disconnect the negative terminal of the battery to prevent electrical issues.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, torque wrench, multimeter.
• Remove the O2 sensor located upstream of the catalytic converter.
  • Use the O2 sensor socket to unscrew it carefully.
  • Inspect the sensor for damage or contamination.
• If faulty, replace with a new OEM or compatible sensor.
• Reinstall and torque to manufacturer's specifications (typically around 30 lb-ft).

3. Inspect and Clean or Replace Catalytic Converter

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter (if needed).
• Raise the vehicle using a jack and secure it with jack stands.
• Remove the exhaust system components leading to the catalytic converter (if applicable).
  • Cut or unbolt as necessary.
• Inspect the catalytic converter for any signs of clogging or damage.
• If the converter is contaminated, consider cleaning it with a catalytic converter cleaner or replace it with an OEM part.
• Reinstall all exhaust components and ensure proper sealing.

4. Clear Codes and Reconnect Battery

• Reconnect the negative terminal of the battery.
• Use the OBD-II scanner to clear the P0420 code.
• Start the vehicle and let it run for a few minutes to ensure everything is functioning correctly.