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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, temperature gun, socket set, jack and jack stands, safety goggles, gloves.
• Gather replacement parts if needed (e.g., catalytic converter, oxygen sensors).

2. Address Exhaust Leaks

• Sub-steps:
  1. Lift the vehicle using a jack and secure it with jack stands.
  2. Visually inspect the exhaust system from the engine to the tailpipe for signs of leaks or holes.
  3. If any leaks are found, repair or replace affected sections using exhaust sealing compounds or clamps.

3. Replace Faulty Oxygen Sensors

• Sub-steps:
  1. Disconnect the battery to prevent electrical issues.
  2. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  3. Use a socket wrench to unscrew the faulty oxygen sensors.
  4. Install the new oxygen sensors and torque them to the manufacturer's specifications (typically around 30 lb-ft).
  5. Reconnect the battery.

4. Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Disconnect any sensors or components connected to the catalytic converter.
  2. Remove bolts securing the catalytic converter using a socket set.
  3. Take out the old catalytic converter and replace it with a new one.
  4. Reinstall the bolts, ensuring they are tightened to the proper torque specifications (usually around 40 lb-ft).
  5. Reconnect any sensors or exhaust components removed.

5. Clear Error Codes

• Sub-steps:
  1. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
  2. Start the vehicle and allow it to reach operating temperature to ensure the system is functioning correctly.