how to fix P0420 code in Toyota Corolla E210 (2019-2024)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.

Tools Required:

• OBD-II scanner
• Multimeter
• Socket set
• Torque wrench
• Jack and jack stands
• Safety glasses and gloves

2. Inspect and Replace Oxygen Sensors

1. Remove the upstream oxygen sensor using a socket wrench.
2. Check the sensor for signs of damage or contamination.
3. If defective, replace with a new OEM oxygen sensor.
4. Reinstall the oxygen sensor and torque to manufacturer specifications.

3. Inspect and Replace Catalytic Converter

1. Raise the vehicle securely using a jack and jack stands.
2. Remove the heat shield covering the catalytic converter if applicable.
3. Unbolt the catalytic converter from the exhaust system using a socket set.
4. Inspect the catalytic converter for damage, and if necessary, replace it.
5. Install the new catalytic converter and torque bolts to specified values.

4. Reconnect Battery and Clear Codes

1. Reconnect the battery terminals securely.
2. Use the OBD-II scanner to clear any trouble codes.
3. Start the engine and let it idle for a few minutes.