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

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface and the engine is cool.
• Gather the necessary tools and parts.
• Disconnect the negative battery terminal to prevent any electrical issues.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, torque wrench, penetrating oil
• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Apply penetrating oil to the sensor threads and allow it to sit for a few minutes.
  3. Use the O2 sensor socket to remove the upstream sensor first. Disconnect the electrical connector.
  4. Install the new sensor by threading it into place and tightening it to the manufacturer’s specifications (usually around 30 Nm).
  5. Repeat the process for the downstream sensor if necessary.

3. Replace the Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust gasket
• Sub-steps:
  1. Locate the catalytic converter in the exhaust system.
  2. Disconnect the exhaust pipes from the catalytic converter by removing the bolts or clamps.
  3. Remove any heat shields or brackets securing the catalytic converter.
  4. Carefully remove the old catalytic converter and inspect the exhaust pipes for damage.
  5. Install the new catalytic converter using a new gasket and torque the bolts to the manufacturer’s specifications.
  6. Reinstall any heat shields or brackets removed during disassembly.

4. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code and any other diagnostic trouble codes.