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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety.
• Allow the vehicle to cool down before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: Oxygen sensor socket, ratchet, torque wrench.
• If upstream or downstream oxygen sensors are faulty:
  1. Locate the oxygen sensors in the exhaust manifold and downstream of the catalytic converter.
  2. Use the oxygen sensor socket to unscrew the faulty sensor.
  3. Install the new sensor by threading it into the exhaust pipe and tightening to the manufacturer’s specified torque (typically 30-40 ft-lbs).
  4. Reconnect the electrical connector.

3. Inspect and Replace the Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust gasket (if needed).
• If the catalytic converter is determined to be defective:
  1. Raise the vehicle securely on jack stands and remove the underbody shield if present.
  2. Disconnect the exhaust pipes from the catalytic converter by removing the bolts (may require penetrating oil).
  3. Remove the catalytic converter from its mounting position.
  4. Install the new catalytic converter, ensuring proper alignment and fit.
  5. Reattach the exhaust pipes and tighten to the specified torque.
  6. Replace any gaskets if necessary to prevent exhaust leaks.

4. Reset the Engine Control Module (ECM)

• Tools Required: OBD-II scanner.
• 1. Reconnect the battery.
• 1. Use the OBD-II scanner to clear the fault codes from the ECM.
• 1. Start the engine and allow it to reach operating temperature.