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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to ensure safety.
• Allow the engine to cool before working on the exhaust system.

2. Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors on the exhaust system.
2. Use a socket wrench to remove the old oxygen sensors.
3. Apply anti-seize compound on the threads of the new sensors.
4. Install the new upstream and downstream oxygen sensors and tighten to manufacturer specifications (typically 30-40 lb-ft).
5. Reconnect the battery.

3. Inspect and Replace Catalytic Converter (if necessary)

1. If the catalytic converter is found to be damaged during inspection, proceed to replace it.
2. Remove any exhaust hangers or brackets securing the exhaust components with a socket set.
3. Disconnect the exhaust pipes from the catalytic converter using a wrench.
4. Remove the catalytic converter and inspect the gasket surfaces for damage.
5. Install the new catalytic converter with a new gasket, ensuring proper alignment.
6. Reconnect the exhaust pipes and tighten to manufacturer specifications.

4. Clear Error Codes

1. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
2. Monitor the vehicle performance over the next few days.