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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the vehicle's battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Using the O2 sensor socket, remove the upstream sensor and then the downstream sensor.
  4. Install the new oxygen sensors and torque them to the manufacturer’s specifications (typically around 30 lb-ft).
  5. Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, jack stands, torque wrench.
• Steps:
  1. Raise the vehicle using a jack and secure it with jack stands.
  2. Locate the catalytic converter and inspect for any physical damage or rust.
  3. If damaged, disconnect the exhaust pipes from the catalytic converter using a socket set.
  4. Remove the catalytic converter from its mounting brackets.
  5. Install the new catalytic converter, ensuring proper alignment with the exhaust pipes.
  6. Torque all bolts to the manufacturer’s specifications (usually around 25-30 lb-ft).
  7. Reconnect any sensors or components that were removed during the process.

4. Clear Codes and Test Drive

• After completing repairs, use the OBD-II scanner to clear the P0420 code.
• Start the vehicle and allow it to reach normal operating temperature.
• Conduct a test drive to ensure that the check engine light does not re-illuminate.