how to fix P0420 code in Toyota Camry XV70 (2018-2024)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent any electrical short circuits.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Remove the electrical connectors from both sensors.
  3. Use an O2 sensor socket to unscrew the upstream sensor first, followed by the downstream sensor.
  4. Install the new oxygen sensors by screwing them in by hand, then tighten them to the manufacturer’s specifications (usually around 30 ft-lbs).
  5. Reconnect the electrical connectors for both oxygen sensors.

3. Inspect and Replace Catalytic Converter (if needed)

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter (if necessary)
• Sub-steps:
  1. Raise the vehicle using a jack and secure it with jack stands.
  2. Remove the bolts connecting the exhaust system to the catalytic converter using a socket set.
  3. If the catalytic converter is welded in place, use an exhaust pipe cutter to remove it.
  4. Install the new catalytic converter by reversing the removal process and ensuring all bolts are torqued to factory specifications.
  5. Reconnect any hangers and ensure the exhaust system is properly aligned.

4. Clear Codes and Test

• Tools Required: OBD-II scanner
• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Start the engine and allow it to reach operating temperature.
  4. Take the vehicle for a test drive to ensure the check engine light does not return.