how to fix P0420 code on Tesla Model S Original (2012-2020)

Learn how to diagnose and fix P0420 exhaust system issue in Tesla Model S. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the parking brake is engaged.
• Disconnect the negative terminal of the battery to prevent any electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Steps:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Use the O2 sensor socket to unscrew and remove the upstream oxygen sensor.
  3. Inspect the sensor for damage or carbon buildup. If defective, replace with a new sensor.
  4. Repeat for the downstream oxygen sensor.
  5. Torque the new sensors to the manufacturer's specifications (usually around 30 lb-ft).

3. Examine Catalytic Converter

• Tools Required: Jack and jack stands, exhaust clamp tool
• Steps:
  1. Safely lift the vehicle using a jack and secure it with jack stands.
  2. Visually inspect the catalytic converter for any physical damage or signs of clogging.
  3. If the converter is damaged or clogged, it will need to be replaced. Remove any exhaust clamps and disconnect the exhaust pipe from the catalytic converter.
  4. Install the new catalytic converter, ensuring a proper fit and secure connections.
  5. Reinstall any exhaust clamps and ensure all connections are tight.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner
• Steps:
  1. Reconnect the negative terminal of the battery.
  2. Use an OBD-II scanner to clear the P0420 code from the system.
  3. Start the vehicle and let it idle for a few minutes to ensure proper function.
  4. Conduct a test drive, monitoring engine performance and checking for the reoccurrence of the check engine light.