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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical issues during repairs.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors: Identify the pre-catalytic and post-catalytic oxygen sensors.
2. Remove the Sensors: Use an oxygen sensor socket or wrench to carefully unscrew the sensors from their locations.
3. Inspect the Sensors: Check for damage or excessive carbon buildup. Replace if necessary.
4. Install New Sensors: Screw in the new sensors and tighten to the manufacturer’s specifications (usually around 30-40 Nm or 22-30 lb-ft).

3. Inspect and Replace Catalytic Converter

1. Remove Exhaust Components: Depending on the design, you may need to remove the exhaust pipe or heat shield to access the catalytic converter.
2. Detach the Catalytic Converter: Unscrew the bolts or nuts securing the catalytic converter to the exhaust system, taking care not to damage any surrounding components.
3. Inspect the Converter: Check for signs of physical damage, clogging, or overheating. If it appears damaged, proceed to replace it.
4. Install New Catalytic Converter: Position the new catalytic converter and secure it with bolts or clamps to the specified torque (usually around 25-35 Nm or 18-26 lb-ft).

4. Reconnect and Test

1. Reconnect Battery: Reattach the negative battery terminal.
2. Clear Codes: Use the OBD-II scanner to clear any stored trouble codes.
3. Test Drive: Drive the vehicle under various conditions to ensure the check engine light does not return and that performance is restored.