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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shocks.

2. Inspect and Replace Oxygen Sensors

1. Remove the upstream oxygen sensor (pre-catalytic converter) using an oxygen sensor socket.
   • Tools Required: Oxygen sensor socket, ratchet, and extension.
2. Install the new upstream oxygen sensor and torque it to the manufacturer’s specifications (usually around 30 ft-lbs).
3. Remove the downstream oxygen sensor (post-catalytic converter) using the same procedure.
4. Install the new downstream oxygen sensor and torque it to specifications.
5. Reconnect the battery.

3. Inspect and Clean the Catalytic Converter

1. If the catalytic converter is suspected to be clogged, remove it from the exhaust system.
   • Tools Required: Socket set, wrench set.
2. Inspect the catalytic converter for physical damage or excessive carbon buildup.
3. Use a catalytic converter cleaner if there is minor buildup, following the manufacturer's instructions.
4. If severely clogged or damaged, replace the catalytic converter with a new one.

4. Reset the Engine Control Module (ECM)

1. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
2. Start the engine and let it run for a few minutes to allow the ECM to recalibrate.