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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors on the exhaust system.
2. Use a socket wrench to remove the sensors from their respective positions.
3. Compare the old sensors with the new ones to ensure compatibility.
4. Install the new oxygen sensors, tightening them to the manufacturer's specifications (typically around 30-40 lb-ft).
5. Reconnect the battery.

3. Replace the Catalytic Converter (if necessary)

1. Raise the vehicle securely using jack stands.
2. Remove the heat shield if applicable, using a socket set.
3. Disconnect the exhaust pipes from both ends of the catalytic converter by loosening the bolts or clamps.
4. Remove the old catalytic converter.
5. Install the new catalytic converter, ensuring proper alignment with the exhaust pipes.
6. Tighten all bolts to the manufacturer's specifications, typically around 20-25 lb-ft for exhaust components.
7. Reinstall the heat shield if removed.