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

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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the vehicle's battery to prevent electrical shorts.
• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench.

2. Inspect and Replace Oxygen Sensors (if faulty)

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors (typically near the catalytic converter).
  2. Disconnect the wiring harness from each oxygen sensor.
  3. Use a socket wrench to remove the sensors from the exhaust system.
  4. Install new oxygen sensors, ensuring they are tightened to the manufacturer's torque specifications.
  5. Reconnect the wiring harnesses to the sensors.

3. Inspect and Replace the Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove any heat shields or covers obstructing access to the catalytic converter.
  2. Unbolt the catalytic converter from the exhaust system using a socket set.
  3. Inspect the exhaust gaskets; replace if damaged.
  4. Install the new catalytic converter, ensuring it is positioned correctly.
  5. Torque the bolts to the manufacturer's specifications.
  6. Reinstall any heat shields or covers that were removed.

4. Reconnect Battery and Clear Codes

• Sub-steps:
  1. Reconnect the vehicle's battery terminals.
  2. Use the OBD-II scanner to clear the P0420 code from the system.
  3. Start the vehicle and allow it to reach operating temperature.