my Toyota Camry Eighth Generation (2018-present) shows code P0420, what does this mean?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to prevent electrical issues.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench, penetrating oil.
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Apply penetrating oil to the sensor threads if stuck.
  3. Use the O2 sensor socket to remove the old sensors.
  4. Install the new sensors by threading them in by hand and then torqueing to manufacturer specifications (typically around 30 ft-lbs).

3. Inspect Catalytic Converter

• Tools Required: Visual inspection tools, jack stands, safety goggles.
• Sub-steps:
  1. Lift the vehicle using a jack and secure it with jack stands.
  2. Visually inspect the catalytic converter for cracks, dents, or signs of overheating.
  3. If damaged, remove the catalytic converter by unbolting it from the exhaust system and exhaust manifold.
  4. Install a new catalytic converter, ensuring all bolts are torqued to specifications.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner.
• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
  3. Start the engine and perform a test drive to ensure proper function and monitor for any reoccurrence of the code.