how to fix Tesla Model 3 Original (2017-2023) check engine light P0420

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, jack, and jack stands.
• Clear the P0420 code using the OBD-II scanner and take the vehicle for a short test drive to see if the light reappears.

2. Inspect and Repair Exhaust Components

• Inspect the Exhaust System:
  • Lift the vehicle safely using a jack and secure it with jack stands.
  • Visually inspect the exhaust system for any visible cracks or leaks.
• Repair Leaks:
  • If leaks are found, use exhaust repair tape or replace damaged sections of the exhaust pipe.

3. Replace Oxygen Sensors (if necessary)

• Remove Old Oxygen Sensors:
  • Disconnect the vehicle battery.
  • Locate the upstream and downstream oxygen sensors.
  • Use the socket set to remove the sensors.
• Install New Oxygen Sensors:
  • Apply anti-seize compound to the threads of the new sensors.
  • Install the new oxygen sensors and torque them to the manufacturer’s specifications.
  • Reconnect the battery.

4. Replace Catalytic Converter (if necessary)

• Remove Old Catalytic Converter:
  • Disconnect the exhaust pipes from the catalytic converter using the socket set.
  • Remove any mounting brackets and bolts securing the catalytic converter.
• Install New Catalytic Converter:
  • Position the new catalytic converter and secure it with the mounting brackets and bolts.
  • Reconnect the exhaust pipes and ensure all connections are tight.

5. Final Checks

• Clear Codes and Test:
  • Reconnect the vehicle battery if it was disconnected.
  • Clear any DTCs using the OBD-II scanner.
  • Start the engine and monitor for any check engine lights or abnormal behavior.