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

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the vehicle's 12V battery to ensure safety during repairs.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream (pre-catalytic converter) oxygen sensor.
  • Use the O2 sensor socket and ratchet to unscrew the sensor.
  • Disconnect the electrical connector.
• Install the new upstream oxygen sensor.
  • Apply anti-seize compound to the threads of the new sensor.
  • Torque to the manufacturer’s specifications (usually around 30 Nm).
• Repeat the process for the downstream (post-catalytic converter) sensor if necessary.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust gasket.
• Remove the catalytic converter.
  • Unbolt the exhaust flanges and any hangers securing the converter.
  • Carefully lower the catalytic converter assembly from the vehicle.
• Inspect the catalytic converter for physical damage or blockage.
• Install the new catalytic converter.
  • Ensure proper alignment and secure all bolts to the specified torque settings.
  • Replace any gaskets if necessary to prevent leaks.

4. Reconnect Battery and Clear Codes

• Reconnect the vehicle's 12V battery.
• Use the OBD-II scanner to clear the P0420 code and any other related codes.

5. Test Drive and Monitor

• Take the vehicle for a test drive to allow the engine to reach operating temperature and monitor for any reoccurring codes.