how to fix P0420 code on my Tesla Model 3 Highland (2024-present)?

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is on a flat surface and securely supported with jack stands if necessary.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Sub-steps:
  1. Disconnect the battery to prevent electrical issues.
  2. Locate the upstream and downstream oxygen sensors in the exhaust system.
  3. Use the O2 sensor socket to remove the upstream oxygen sensor first.
  4. Install the new upstream oxygen sensor and torque it to the manufacturer’s specifications (typically around 30 lb-ft).
  5. Repeat for the downstream oxygen sensor, ensuring it is properly secured.

3. Inspect the Catalytic Converter

• Tools Required: Torque wrench, inspection mirror
• Sub-steps:
  1. Check for physical damage or signs of blockage in the catalytic converter.
  2. If damaged, remove the catalytic converter by unbolting it from the exhaust system.
  3. Install the new catalytic converter and torque the bolts to the manufacturer’s specifications.

4. Clear Error Codes

• Tools Required: OBD-II scanner
• Sub-steps:
  1. Reconnect the battery if disconnected.
  2. Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.

5. Test Drive

• Perform a test drive to ensure that the repair has resolved the issue and the check engine light does not reappear.