my Tesla Model S Plaid/Refresh (2021-present) has a P0420 code, how to fix it?

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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery to ensure safety during repairs.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Use a wrench to carefully remove the sensors from their respective mounting locations.
  3. Inspect the sensors for damage or contamination.
  4. Install new oxygen sensors by threading them into the exhaust system and tightening them to the manufacturer's specifications (typically around 30 lb-ft).
• Tools Required:
  • Oxygen sensor socket
  • Torque wrench

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove the exhaust system components that obstruct access to the catalytic converter.
  2. Disconnect the catalytic converter from the exhaust manifold and exhaust pipe using appropriate tools.
  3. Inspect the catalytic converter for signs of damage, such as physical dents or internal breakdown.
  4. Install the new catalytic converter, ensuring proper alignment and sealing.
  5. Reconnect all exhaust components and fasten them securely.
• Tools Required:
  • Socket set
  • Wrench set
  • Gasket scraper (if needed)

4. Reconnect Battery and Clear Codes

• Sub-steps:
  1. Reconnect the vehicle’s battery terminals.
  2. Use an OBD-II scanner to clear the P0420 code from the system.
  3. Perform a test drive to monitor vehicle performance and check for reoccurrence of the code.