how to fix P0420 code on my Tesla Model S Plaid/Refresh (2021-present)

Learn how to diagnose and fix P0420 catalytic converter 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.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal for safety.

2. Inspect and Replace Oxygen Sensors

1. Locate Oxygen Sensors
   • Identify the upstream and downstream oxygen sensors in the exhaust system.
2. Remove Oxygen Sensors
   • Use an O2 sensor socket to carefully unscrew both the upstream and downstream sensors.
3. Inspect Sensors
   • Examine sensors for signs of contamination or damage.
4. Install New Sensors
   • Apply anti-seize compound to the threads of new sensors (if applicable).
   • Install the upstream and downstream sensors and torque to the manufacturer's specifications (typically around 30-40 ft-lbs).

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove Exhaust Components
   • Unbolt the exhaust system components connected to the catalytic converter using a socket set.
2. Remove Catalytic Converter
   • Carefully detach the catalytic converter from the exhaust system.
3. Inspect and Install New Catalytic Converter
   • Inspect the new catalytic converter for damage.
   • Install the new catalytic converter and torque the bolts to manufacturer specifications.

4. Reconnect Battery

• Reconnect the negative battery terminal securely.

5. Clear Codes and Test Drive

• Use the OBD-II scanner to clear the P0420 code.
• Take the vehicle for a test drive to ensure that the check engine light does not reappear.