how to fix P0420 code on my Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery before starting work.

2. Inspect and Replace Oxygen Sensors (if faulty)

1. Locate the upstream and downstream oxygen sensors.
2. Use a socket wrench to remove the old oxygen sensors.
3. Install new oxygen sensors, applying anti-seize compound to the threads.
4. Torque the sensors to the manufacturer's specifications (typically around 30 lb-ft).
5. Reconnect the battery.

3. Inspect and Replace Catalytic Converter (if faulty)

1. Raise the vehicle securely on jack stands.
2. Remove any heat shields if necessary to access the catalytic converter.
3. Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe using a socket set.
4. Inspect the old catalytic converter for blockages or damage.
5. Install the new catalytic converter, ensuring proper alignment.
6. Torque the bolts to the manufacturer's specifications (usually around 40 lb-ft).
7. Reinstall any heat shields that were removed.

4. Clear Error Codes

1. Use an OBD-II scanner to clear the P0420 code from the vehicle's computer.
2. Start the engine and let it idle for a few minutes to ensure no leaks are present.