what does code P0420 mean for my Honda Pilot YF3 (2016-2022)

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench, multimeter
• Remove the upstream oxygen sensor (before the catalytic converter).
  • Disconnect the sensor’s electrical connector.
  • Use the O2 sensor socket to unscrew the sensor from the exhaust pipe.
• Install the new oxygen sensor.
  • Apply anti-seize compound on the threads of the new sensor.
  • Screw it in place and connect the electrical connector.
• Repeat for the downstream oxygen sensor if necessary.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, cutting tools (if necessary)
• Remove the exhaust system components that obstruct access to the catalytic converter.
• Disconnect the catalytic converter from the exhaust manifold and exhaust pipe.
• Install the new catalytic converter.
  • Ensure all gaskets and seals are in place.
  • Tighten bolts to the manufacturer's specified torque values.
• Reinstall any removed exhaust components.

4. Clearing the Code

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code from the memory.