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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench.
• Steps:
  • Disconnect the battery to ensure safety while working on electrical components.
  • Gather all necessary tools and replacement parts.

2. Inspect and Replace Oxygen Sensors

• Steps:
  • Remove the downstream oxygen sensor from the catalytic converter using a socket wrench.
  • Inspect the sensor for signs of damage or contamination.
  • If necessary, replace the downstream oxygen sensor with a new one.
  • Torque the new oxygen sensor to the manufacturer's specifications (usually around 30 ft-lbs).

3. Inspect and Replace the Catalytic Converter

• Steps:
  • Remove any heat shields or brackets that may obstruct access to the catalytic converter.
  • Disconnect the exhaust pipes from both ends of the catalytic converter using a socket set.
  • Remove the catalytic converter from the vehicle.
  • Install the new catalytic converter, ensuring proper alignment with the exhaust pipes.
  • Torque all connections to the manufacturer's specifications (typically around 30 ft-lbs).
  • Reinstall any heat shields or brackets removed earlier.

4. Reconnect Battery and Clear Codes

• Steps:
  • Reconnect the battery.
  • Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
  • Start the engine and allow it to reach operating temperature.