how to fix P0420 code in Tesla Model 3 Original (2017-2023)

Solution

1. Preparation

• Gather tools and parts for the repair.
• Disconnect the negative battery terminal to ensure safety while working on the electrical components.

2. Replace Faulty Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, and torque wrench.
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Using the O2 sensor socket, carefully unscrew the faulty oxygen sensors.
  3. Install the new oxygen sensors by threading them into place and tightening them to the manufacturer's specified torque (usually around 30-40 Nm).
  4. Reconnect the electrical connectors to the new sensors.

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

• Tools Required: Socket set, torque wrench, exhaust gasket sealant.
• Sub-steps:
  1. Remove any heat shields or protective covers from the catalytic converter.
  2. Disconnect the exhaust pipes from the catalytic converter by removing the bolts or clamps.
  3. Remove the old catalytic converter and inspect the mounting surfaces for damage or carbon buildup.
  4. Install the new catalytic converter with the appropriate gaskets, ensuring all bolts are tightened to the specified torque (typically around 25-30 Nm).
  5. Reinstall any heat shields or protective covers.

4. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the system.
• Start the vehicle and allow it to reach operating temperature.