what does code P0420 mean on my Tesla Model 3 Highland (2024-present)

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the vehicle's battery to avoid any electrical issues while working.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  • Locate the upstream and downstream oxygen sensors.
  • Disconnect the electrical connectors from both sensors.
  • Use a wrench to remove the sensors from the exhaust manifold and catalytic converter.
  • Install new oxygen sensors and tighten to manufacturer specifications (typically around 30 ft-lbs).
  • Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  • Locate the catalytic converter in the exhaust system.
  • Remove any heat shields or brackets as necessary.
  • Use a wrench to remove the bolts securing the catalytic converter to the exhaust pipes.
  • Carefully remove the old catalytic converter.
  • Install the new catalytic converter, ensuring proper alignment.
  • Torque the bolts to manufacturer specifications (usually around 40-50 ft-lbs).
  • Replace heat shields and brackets.

4. Reset the OBD-II System

• Sub-steps:
  • Reconnect the vehicle's battery.
  • Use the OBD-II scanner to clear any diagnostic trouble codes.