how to fix P0420 code in my Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, exhaust system cleaner.
• Ensure the vehicle is on a flat surface and the engine is cool before starting the work.
• Disconnect the negative battery terminal to reset the vehicle's computer.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Unplug the electrical connectors from both sensors.
  3. Use a socket wrench to remove the sensors from their respective locations.
  4. Install the new oxygen sensors, tightening them to manufacturer specifications (typically around 30-40 ft-lbs).
  5. Reconnect the electrical connectors securely.

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

• Sub-steps:
  1. Inspect the catalytic converter for signs of damage, such as dents or rust.
  2. If damaged, remove the catalytic converter by loosening the bolts that connect it to the exhaust pipe and manifold.
  3. Install the new catalytic converter, ensuring proper alignment and sealing.
  4. Torque the bolts to manufacturer specifications (typically around 40-50 ft-lbs).

4. Reset the Engine Control Module (ECM)

• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Start the engine and allow it to idle for a few minutes to ensure all systems are functioning properly.
  3. Drive the vehicle for a short distance (10-15 miles) to allow the ECM to recalibrate.