how to fix P0420 code on my Toyota Camry Eighth Generation (2018-present)

Solution

1. Preparation

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

2. Inspect and Replace O2 Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Use a socket wrench to disconnect the electrical connectors from both O2 sensors.
  3. Remove the sensors using an O2 sensor socket or a wrench.
  4. Install new O2 sensors (ensure they are compatible with the vehicle).
  5. Reconnect the electrical connectors securely.

3. Inspect and Replace the Catalytic Converter

• Sub-steps:
  1. Elevate the vehicle using jack stands for access to the exhaust system.
  2. Remove any heat shields or brackets securing the catalytic converter.
  3. Use a cutting tool to carefully detach the catalytic converter from the exhaust pipes if necessary.
  4. Install the new catalytic converter, ensuring it fits correctly and seals properly.
  5. Reattach heat shields and brackets as necessary.
  6. Reconnect the exhaust pipes using the appropriate gaskets and fasteners.

4. Reconnect Battery and Clear Codes

• Sub-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 engine and let it idle for a few minutes to ensure proper operation.