my Tesla Model 3 Highland (2024-present) shows P0420 code, what does it mean

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery to ensure safety.
• Allow the exhaust system to cool before starting work.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench, multimeter.
• Remove the upstream oxygen sensor (pre-catalytic converter):
  1. Locate the sensor in the exhaust pipe.
  2. Use the O2 sensor socket to unscrew it carefully.
  3. Install the new sensor and torque to manufacturer's specifications (typically 30-40 lb-ft).
• Repeat for the downstream sensor if necessary.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter.
• Remove the catalytic converter:
  1. Disconnect any exhaust hangers or brackets.
  2. Cut exhaust pipes as necessary to remove the old catalytic converter.
  3. Install the new catalytic converter, ensuring proper alignment.
  4. Reconnect exhaust pipes and torque bolts to manufacturer specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the vehicle's battery.
• Use the OBD-II scanner to clear the P0420 code and any other diagnostic trouble codes.