what does a P0420 code mean for my Honda Pilot YF4 (2023-Present)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Ensure the vehicle is parked on a level surface and set the parking brake.
• Disconnect the battery to avoid electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from both oxygen sensors.
  3. Remove the sensors using an oxygen sensor socket or wrench.
  4. Install new oxygen sensors using anti-seize compound on the threads, and torque them to manufacturer's specifications (typically around 30 lb-ft).

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  1. Locate the catalytic converter and inspect it for damage.
  2. If damaged, remove the exhaust pipes attached to the catalytic converter, typically using a socket set.
  3. Install the new catalytic converter, ensuring proper alignment and sealing.
  4. Torque the exhaust connections to the manufacturer’s specifications.

4. Clear Diagnostic Codes

• Sub-steps:
  1. Reconnect the battery if it was disconnected.
  2. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.