what does error code P0420 mean for my Honda Pilot Third Generation (2016-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery to ensure safety while working on electrical components.

2. Inspect and Replace the Oxygen Sensors

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter.
• Remove the upstream and downstream oxygen sensors using the appropriate socket.
• Test each sensor with a multimeter to ensure they are operating within specifications.
• If faulty, replace with new OEM or quality aftermarket oxygen sensors.
• Torque the new sensors to the manufacturer's specifications.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if necessary).
• Remove any exhaust components connected to the catalytic converter, ensuring to support the exhaust system to prevent sagging.
• Disconnect the catalytic converter from the exhaust manifold and the exhaust pipe.
• Inspect the old catalytic converter for damage; if needed, replace it with an OEM part.
• Install the new catalytic converter and reconnect all exhaust components, ensuring all bolts are torqued to manufacturer specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the vehicle's battery.
• Use the OBD-II scanner to clear the P0420 error code from the system.