how to fix P0420 code on my Honda Accord 9th Generation (2013-2017)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to prevent any electrical issues during repair.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the pre-catalytic and post-catalytic oxygen sensors:
  • Locate the sensors on the exhaust system.
  • Use the O2 sensor socket to unscrew the sensors from their respective locations.
• Install new oxygen sensors:
  • Apply anti-seize compound to the threads of the new sensors.
  • Torque the sensors to the manufacturer's specifications (usually around 30-40 lb-ft).

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, jack stands, cutting tool (if necessary)
• Remove the catalytic converter:
  • Raise the vehicle securely on jack stands.
  • Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe.
  • If necessary, use a cutting tool to remove any welded sections.
• Install the new catalytic converter:
  • Position the new catalytic converter in place and secure it with bolts.
  • Ensure all gaskets are replaced to prevent exhaust leaks.
  • Torque bolts to the manufacturer’s specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0420 code and any other related codes.