how to fix P0420 code on Toyota Camry Seventh Generation (2012-2017)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to ensure safety.
• Allow the exhaust system to cool before starting work.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet and extensions, torque wrench.
• Remove the upstream (pre-catalytic converter) O2 sensor:
  1. Disconnect the electrical connector.
  2. Use the O2 sensor socket to unscrew the sensor from the exhaust manifold.
• Install the new O2 sensor:
  1. Apply anti-seize compound to the threads (if not pre-applied).
  2. Screw the new sensor in place and tighten to the manufacturer’s specified torque (typically around 30 lb-ft).
  3. Reconnect the electrical connector.
• Repeat this process for the downstream (post-catalytic converter) O2 sensor if it is also faulty.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter or saw, new gaskets.
• Lift the vehicle securely and access the catalytic converter.
• Remove any heat shields that may obstruct access.
• Disconnect the exhaust pipes from the catalytic converter using the socket set.
• Cut the exhaust pipe if necessary, ensuring a clean cut for the new installation.
• Remove the old catalytic converter and install the new one, ensuring proper alignment.
• Use new gaskets to prevent leaks and tighten bolts to the specified torque.

4. Clear Codes and Test

• Reconnect the negative battery terminal.
• Use an OBD-II scanner to clear the stored codes.
• Start the engine and allow it to reach operating temperature.
• Perform a test drive to verify that the check engine light does not reappear.