how to fix P0420 code in my Toyota RAV4 XA50 (2019-2024)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the vehicle’s battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

1. Remove the upstream oxygen sensor:
   • Use an oxygen sensor socket and ratchet to carefully unscrew the sensor from the exhaust manifold.
2. Install the new oxygen sensor:
   • Apply anti-seize compound on the threads of the new oxygen sensor.
   • Install and torque to the manufacturer's specification (typically around 30-40 ft-lbs).
3. Repeat for the downstream oxygen sensor if it is also faulty.

3. Inspect and Replace the Catalytic Converter

1. Remove the old catalytic converter:
   • Unbolt the exhaust pipe and brackets securing the catalytic converter using a socket set.
   • If necessary, cut the exhaust pipe as a last resort if bolts are rusted.
2. Install the new catalytic converter:
   • Position the new catalytic converter and secure it with the bolts.
   • Ensure all gaskets are replaced and the system is sealed to avoid leaks.
3. Torque all bolts to manufacturer specifications.

4. Reconnect Battery and Clear Codes

1. Reconnect the vehicle battery.
2. Use the OBD-II scanner to clear any fault codes from the engine control module (ECM).