how to fix P0420 code in my Honda Pilot YF3 (2016-2022)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Replace Oxygen Sensors (if necessary)

• Tools Required: Oxygen sensor socket, ratchet, extension.
• Remove the upstream oxygen sensor by locating it on the exhaust manifold, using the oxygen sensor socket.
• Install the new oxygen sensor and tighten it to manufacturer specifications (typically 30-40 lb-ft).
• Repeat for the downstream oxygen sensor if it is faulty.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust hanger removal tool.
• Remove the exhaust bolts securing the catalytic converter to the exhaust manifold and the exhaust pipe.
• Carefully remove the catalytic converter from the vehicle.
• Install the new catalytic converter in reverse order, ensuring all gaskets are replaced and bolts are torqued to manufacturer specifications (usually around 30-35 lb-ft).
• Reattach any exhaust hangers removed during the process.

4. Reset the Check Engine Light

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the computer.