how to fix P0420 code in Tesla Model S Original (2012-2020)

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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, jack stands.
• Disconnect the vehicle’s high-voltage battery to ensure safety while working on electrical components.

2. Replace Oxygen Sensor(s) (if faulty)

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Use a socket wrench to remove the faulty oxygen sensor(s).
  3. Install the new oxygen sensor(s) and tighten to manufacturer specifications (usually around 30 lb-ft).
  4. Reconnect the electrical connectors.

3. Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Raise the vehicle securely on jack stands and remove the underbody shield if necessary.
  2. Disconnect the exhaust pipes from the catalytic converter by removing the bolts and flange.
  3. Remove the mounting bolts securing the catalytic converter to the exhaust system.
  4. Install the new catalytic converter and torque the bolts to manufacturer specifications.
  5. Reconnect the exhaust pipes and ensure all connections are tight and leak-free.

4. Reset the Engine Control Module (ECM)

• Sub-steps:
  1. Reconnect the high-voltage battery.
  2. Use the OBD-II scanner to clear the P0420 code from the ECM.
  3. Perform a test drive to allow the ECM to re-evaluate the catalytic converter’s efficiency.