how to fix P0420 code on Honda Accord 9th Generation (2013-2017)

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 in the exhaust system.
2. Use a wrench to disconnect the electrical connectors from both sensors.
3. Remove the sensors using an oxygen sensor socket.
4. Install new oxygen sensors by reversing the removal process.
5. Torque the sensors to the manufacturer's specifications (typically around 30 ft-lbs).

3. Inspect and Replace Catalytic Converter

1. Remove the exhaust pipe leading to the catalytic converter using a socket set.
2. Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe.
3. Inspect the catalytic converter for physical damage or clogs.
4. If necessary, replace the catalytic converter with a new one, ensuring it meets OEM specifications.
5. Reinstall the exhaust pipe and torque to the specified values.

4. Clear Codes

1. Reconnect the battery.
2. Use the OBD-II scanner to clear the P0420 code from the system.
3. Start the engine and allow it to reach operating temperature.