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

Solution

1. Preparation

• Gather required tools and parts.
• Ensure the vehicle is on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical issues.

2. Inspect Exhaust System

• Use a jack and jack stands to elevate the vehicle as necessary.
• Visually inspect the exhaust pipes and joints for leaks or damage.
• Tighten any loose connections and replace any damaged sections.

3. Check Oxygen Sensors

• Locate the upstream and downstream oxygen sensors on the exhaust system.
• Disconnect the electrical connectors from both sensors.
• Use a multimeter to measure the voltage output (should fluctuate between 0.1V to 0.9V for the upstream sensor and remain relatively stable for the downstream sensor).
• Replace any faulty sensors as necessary.

4. Replace Catalytic Converter (if needed)

• If the catalytic converter is determined to be faulty:
  • Remove any exhaust components obstructing access to the catalytic converter.
  • Unbolt and remove the catalytic converter from the exhaust system.
  • Install the new catalytic converter, ensuring proper alignment.
  • Torque the bolts to the manufacturer specifications (typically around 30-40 ft-lbs, but consult the service manual for exact values).

5. Reconnect Components

• Reconnect the oxygen sensors and ensure the wiring is secured and free from damage.
• Reconnect the battery and clear the trouble codes using an OBD-II scanner.