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

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, ratchet and extension, torque wrench.
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors; they are typically found on the exhaust manifold and near the catalytic converter, respectively.
  2. Disconnect the electrical connectors from the sensors.
  3. Using the O2 sensor socket, carefully remove the sensors from their respective locations.
  4. Install the new oxygen sensors by threading them by hand to avoid cross-threading.
  5. Tighten the sensors to the manufacturer's torque specifications (usually around 30-40 ft-lbs).
  6. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack and jack stands, torque wrench.
• Sub-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 excessive soot buildup.
  3. If replacement is needed, unbolt the catalytic converter from the exhaust system using the socket set.
  4. Install the new catalytic converter, ensuring proper alignment with the exhaust pipes.
  5. Tighten the bolts to the manufacturer's specified torque.
  6. Lower the vehicle back to the ground.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner.
• Sub-steps:
  1. Reconnect the vehicle's battery.
  2. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
  3. Start the engine and allow it to run for a few minutes to check for any returning codes.
  4. Take the vehicle for a test drive under various conditions to ensure the issue is resolved.