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

Solution

1. Preparation

• Gather tools including an OBD-II scanner, multimeter, socket set, and jack stands.
• Ensure the vehicle is parked on a level surface with the engine off and cool.

2. Inspect and Repair Exhaust System

• Step 1: Check for exhaust leaks.
  • Inspect all connections and joints in the exhaust system.
  • Use exhaust leak detection fluid if necessary.
• Step 2: Repair any leaks found.
  • Replace damaged gaskets or clamps.
  • Use exhaust repair tape or welding for small holes.

3. Replace Oxygen Sensors (if necessary)

• Step 1: Disconnect the battery.
  • Remove the negative terminal to prevent electrical shorts.
• Step 2: Remove the upstream and downstream oxygen sensors.
  • Use a socket wrench to unscrew the sensors from their respective locations.
• Step 3: Install the new sensors.
  • Apply anti-seize compound to the threads of the new sensors.
  • Tighten to the manufacturer's specifications, typically around 30 ft-lbs.

4. Replace Catalytic Converter (if necessary)

• Step 1: Remove the old catalytic converter.
  • Unbolt the converter from the exhaust system using a socket set.
• Step 2: Install the new catalytic converter.
  • Align the new converter and secure it with bolts.
  • Torque the bolts to the manufacturer's specifications.

5. Clear Error Codes

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code from the computer.