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

Solution

1. Preparation

• Gather tools and parts needed.
• Disconnect the battery to ensure safety.
• Raise the vehicle on jack stands for access to the exhaust system.

Tools Required:

• OBD-II scanner
• Multimeter
• Infrared thermometer
• Socket set
• Torque wrench
• Jack stands

2. Inspect and Replace Oxygen Sensors

1. Locate the oxygen sensors (usually near the exhaust manifold and after the catalytic converter).
2. Disconnect the electrical connectors from both the upstream and downstream oxygen sensors.
3. Remove the sensors using a socket wrench.
4. Install new oxygen sensors, tightening them to the manufacturer’s specified torque.
5. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter

1. Remove any heat shields covering the catalytic converter, if applicable.
2. Disconnect the exhaust pipes connected to the catalytic converter using a socket set.
3. Remove the catalytic converter from the vehicle.
4. Install the new catalytic converter, ensuring proper alignment.
5. Reconnect the exhaust pipes and tighten the bolts to the specified torque.
6. Reinstall heat shields if removed.

4. Reset the Check Engine Light

1. Reconnect the battery.
2. Use the OBD-II scanner to clear the P0420 code from the vehicle’s memory.
3. Start the engine and let it reach operating temperature.