my Honda Pilot Third Generation (2016-present) has a check engine light with P0420 code, what's wron...

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to ensure safety during repairs.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors.
2. Disconnect the electrical connectors from both sensors.
3. Remove the sensors using an oxygen sensor socket.
4. Install the new sensors, ensuring they are tightened to the manufacturer’s torque specifications (usually around 30 lb-ft).
5. Reconnect the electrical connectors.

3. Inspect and Replace the Catalytic Converter (if necessary)

1. Confirm that the catalytic converter is indeed faulty based on diagnostic findings.
2. Raise the vehicle using jack stands for access to the exhaust system.
3. Remove any heat shields if applicable.
4. Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe.
5. Install the new catalytic converter, ensuring proper alignment.
6. Torque the bolts to the manufacturer's specifications (usually around 25-30 lb-ft).

4. Clear Codes and Test

1. Reconnect the vehicle battery.
2. Use the OBD-II scanner to clear the P0420 code from the ECU.
3. Start the engine and allow it to reach operating temperature.
4. Monitor the vehicle for any reoccurrence of the check engine light.