my Honda Accord Eleventh Generation (2023-present) check engine light is on with code P0420 what’s w...

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts during repairs.
• Allow the vehicle to cool down before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors (if faulty)

1. Locate the upstream and downstream oxygen sensors in the exhaust system.
2. Unplug the electrical connectors from the sensors.
3. Use an O2 sensor socket to remove the sensors from the exhaust manifold and catalytic converter.
4. Install the new oxygen sensors, tightening them to the manufacturer’s specifications (typically around 30-40 lb-ft).
5. Reconnect the electrical connectors to the new sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

1. If the catalytic converter is damaged or clogged, locate it in the exhaust system.
2. Disconnect the exhaust pipes connected to the catalytic converter using a socket set.
3. Remove any mounting bolts or brackets holding the catalytic converter in place.
4. Install the new catalytic converter, ensuring proper alignment with the exhaust pipes.
5. Reattach any bolts or brackets and tighten to the manufacturer’s specifications.

4. Reconnect Battery and Reset Codes

1. Reconnect the negative battery terminal securely.
2. Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
3. Start the engine and allow it to reach operating temperature.