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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, infrared thermometer, jack and jack stands, safety goggles, gloves.
• Disconnect the battery negative terminal to prevent electrical shorts.
• Raise the vehicle using a jack and secure it with jack stands.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors on the exhaust system.
2. Disconnect the electrical connectors from both oxygen sensors.
3. Use a socket wrench to remove the sensors from their respective bungs.
4. Inspect the sensor tips for contamination or damage.
5. Install new oxygen sensors (if necessary) and torque them to manufacturer specifications (usually around 30-40 ft-lbs).
6. Reconnect the electrical connectors.

3. Inspect and Replace the Catalytic Converter

1. Inspect the catalytic converter for physical damage or clogging.
2. If necessary, remove the exhaust pipe sections connecting to the catalytic converter. This may involve removing bolts or clamps.
3. Use a socket wrench to remove the catalytic converter from the exhaust system.
4. Install the new catalytic converter, ensuring it is oriented correctly, and torque the bolts to manufacturer specifications (usually around 25-30 ft-lbs).
5. Reconnect any exhaust pipe sections removed earlier.

4. Clear Codes and Test Drive

1. Reconnect the battery terminal.
2. Use the OBD-II scanner to clear the P0420 code from the ECU.
3. Start the engine and let it warm up to operating temperature.
4. Conduct a test drive to ensure no check engine light returns and the vehicle performs correctly.