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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench, multimeter.
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use the O2 sensor socket to remove the sensors from the exhaust pipes.
  4. Install new oxygen sensors by screwing them into place and reconnecting the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, pry bar, jack stands, safety goggles, gloves.
• Sub-steps:
  1. Raise the vehicle securely using jack stands.
  2. Remove the heat shield if applicable to access the catalytic converter.
  3. Unbolt the catalytic converter from both the exhaust manifold and the exhaust pipe.
  4. Inspect the catalytic converter for signs of damage or blockage.
  5. Install the new catalytic converter in reverse order, ensuring all bolts are torqued to manufacturer specifications.

4. Clear Error Codes

• Connect the OBD-II scanner and clear the P0420 code from the vehicle’s computer.
• Reconnect the negative battery terminal.