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

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, socket set, torque wrench, safety glasses, and gloves.
• Ensure the vehicle is parked on a flat surface and the engine is cool.

2. Inspect and Replace Oxygen Sensors

1. Disconnect Battery: Disconnect the negative terminal to avoid electrical short circuits.
2. Locate Oxygen Sensors: Find the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
3. Remove Sensors:
   • Use the appropriate socket to unscrew the oxygen sensors from their respective locations.
   • Carefully disconnect the electrical connectors.
4. Install New Sensors:
   • Apply anti-seize compound on the threads of the new oxygen sensors.
   • Install and torque to the manufacturer’s specifications (usually around 30 lb-ft).
   • Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove Exhaust Components:
   • Loosen and remove any clamps or bolts holding the catalytic converter in place.
   • Carefully detach the catalytic converter from the exhaust system.
2. Inspect Catalytic Converter:
   • Check for physical damage, blockage, or contamination.
   • If damaged, replace with a new catalytic converter.
3. Install New Catalytic Converter:
   • Position the new catalytic converter and secure it with clamps or bolts.
   • Torque the bolts to the manufacturer's specifications (usually around 30-35 lb-ft).

4. Clear Codes and Test

1. Reconnect Battery: Reconnect the negative battery terminal.
2. Clear Codes: Use the OBD-II scanner to clear the P0420 code.
3. Test Drive: Drive the vehicle under various conditions to ensure the check engine light does not reappear.