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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the vehicle battery to ensure safety while working on the electrical systems.

2. Inspect and Repair Exhaust Leaks

• Sub-steps:
  • Visually inspect the exhaust pipes and joints for any signs of damage or leaks.
  • Use an exhaust leak detector spray or soap solution to identify leaks.
  • If leaks are found, tighten connections or replace faulty gaskets or components.

3. Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, wrench
• Sub-steps:
  • Locate the upstream and downstream oxygen sensors.
  • Disconnect the electrical connectors from the sensors.
  • Using the O2 sensor socket, unscrew the sensors from the exhaust system.
  • Install the new sensors by screwing them into place and reconnecting the electrical connectors.

4. Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, cutting tool (if necessary), new gaskets
• Sub-steps:
  • Remove the exhaust pipe connected to the catalytic converter using a socket set.
  • If necessary, cut the old catalytic converter from the exhaust pipe.
  • Install the new catalytic converter with new gaskets, ensuring all connections are tight.
  • Reattach the exhaust pipe securely.

5. Reset the ECU

• Sub-steps:
  • Reconnect the vehicle battery.
  • Use an OBD-II scanner to clear the P0420 code from the ECU.