how to fix P0420 code Honda Pilot YF4 (2023-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety during repairs.
• Raise the vehicle using a jack and secure it on jack stands.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, socket set.
• Remove the upstream and downstream oxygen sensors by using the O2 sensor socket.
• Inspect the sensors for damage or contamination.
• If faulty, replace with OEM or high-quality aftermarket oxygen sensors.
• Reconnect the sensors securely.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, exhaust pipe cutter (if needed), gasket scraper, torque wrench.
• Remove the exhaust pipe connected to the catalytic converter by unbolting it. Use penetrating oil if bolts are rusted.
• Inspect the catalytic converter for physical damage or clogging.
• If replacement is needed, install the new catalytic converter in place of the old one, ensuring proper alignment.
• Use a gasket scraper to clean the mating surfaces and install new gaskets.
• Torque bolts to the manufacturer's specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code and any other related codes.
• Start the engine and let it idle for a few minutes.