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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, back pressure gauge.
• Ensure the vehicle is on a level surface and the engine is cool.
• Disconnect the vehicle's battery to avoid any electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Remove the engine cover if applicable to access the oxygen sensors.
  2. Disconnect the electrical connectors from the upstream and downstream oxygen sensors.
  3. Use a socket wrench to remove the sensors from the exhaust system.
  4. Install the new oxygen sensors, ensuring they are tightened to manufacturer specifications (usually around 30 ft-lbs).
  5. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  1. Remove any heat shields or covers protecting the catalytic converter.
  2. Use a socket set to unbolt the catalytic converter from the exhaust system.
  3. Inspect the exhaust flanges for flatness; replace gaskets if necessary.
  4. Install the new catalytic converter, ensuring proper alignment and torque (typically 25-30 ft-lbs).
  5. Reinstall any heat shields or covers.

4. Final Steps

• Reconnect the vehicle’s battery.
• Clear the P0420 code using the OBD-II scanner.
• Start the engine and allow it to reach operating temperature while monitoring for any exhaust leaks.