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

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the negative terminal of the battery to prevent electrical shorts during repair.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream oxygen sensor:
  1. Locate the upstream O2 sensor (usually near the exhaust manifold).
  2. Use the O2 sensor socket to unscrew the sensor.
  3. Install the new oxygen sensor and torque to manufacturer specifications (typically around 30 ft-lbs).
• Repeat for the downstream oxygen sensor.

3. Inspect and Replace Catalytic Converter (if required)

• Tools Required: Socket set, torque wrench, exhaust sealant.
• Remove the old catalytic converter:
  1. Disconnect any bolts or clamps securing the catalytic converter to the exhaust system.
  2. Remove the catalytic converter from the vehicle, ensuring to catch any remaining exhaust gases safely.
• Install the new catalytic converter:
  1. Position the new catalytic converter in place and secure it with bolts or clamps.
  2. Torque the bolts to manufacturer specifications (usually between 25-35 ft-lbs).
  3. Apply exhaust sealant if necessary to ensure a proper seal.

4. Reconnect Battery and Clear Codes

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