how to fix the P0420 code on my 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 level surface and engage the parking brake.
• Disconnect the battery to avoid electrical shorts during the repair.

2. Inspect and Replace O2 Sensors

• Tools Required: O2 sensor socket, wrench set.
• Remove the upstream O2 sensor:
  1. Locate the upstream O2 sensor.
  2. Use the O2 sensor socket to unscrew and remove the sensor.
• Install the new upstream O2 sensor:
  1. Apply anti-seize compound to the threads of the new O2 sensor.
  2. Screw in the new sensor and tighten it to the manufacturer's specifications (usually around 30 lb-ft).
• Repeat the process for the downstream O2 sensor if it is faulty.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, jack stands, exhaust gasket (if necessary).
• Raise the vehicle using a jack and secure it with jack stands.
• Locate the catalytic converter and visually inspect it:
  1. Look for dents, cracks, or rust.
  2. Tap gently with a rubber mallet to check for internal damage (a rattling sound may indicate failure).
• If replacement is necessary, remove the catalytic converter:
  1. Unbolt the exhaust flanges and any brackets holding it in place.
  2. Remove the old catalytic converter.
• Install the new catalytic converter:
  1. Position it in place and secure with new bolts and gaskets if required.
  2. Torque the bolts to the manufacturer's specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use an OBD-II scanner to clear the P0420 code.
• Start the engine and let it idle for a few minutes.