how to fix P0420 code in my Honda Pilot Third Generation (2016-present)?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to ensure safety.

2. Inspect and Replace Oxygen Sensors

1. Remove the upstream and downstream oxygen sensors using a socket wrench.
2. Inspect the sensors for damage or carbon buildup.
3. If faulty, replace them with new sensors.
   • Tools Required: O2 sensor socket, wrench set.
   • Safety Warning: Ensure the exhaust system is cool before working.

3. Inspect and Replace the Catalytic Converter

1. Visually inspect the catalytic converter for any signs of physical damage or excessive carbon buildup.
2. If replacement is necessary, unbolt the catalytic converter from the exhaust system (may require cutting if rusted).
3. Install the new catalytic converter, ensuring that all gaskets and seals are in good condition.
4. Torque bolts to the manufacturer’s specifications.
   • Tools Required: Socket set, torque wrench.
   • Safety Warning: Use protective eyewear and gloves.

4. Reconnect Battery and Clear Codes

1. Reconnect the battery terminals.
2. Use the OBD-II scanner to clear the P0420 trouble code.
3. Ensure all connections are secure.