how to fix P0420 code on Honda Civic 11th Generation (2022-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety during repairs.

Tools Required:

• OBD-II scanner
• Multimeter
• Socket set
• Torque wrench
• Smoke machine (optional)

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Unplug the electrical connectors of the oxygen sensors.
  3. Use a socket wrench to remove the sensors from the exhaust system.
  4. Install new oxygen sensors, ensuring they are torqued to manufacturer's specifications.
  5. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  1. Support the vehicle securely on jack stands.
  2. Remove the exhaust pipes connected to the catalytic converter using a socket set.
  3. Unbolt the catalytic converter from its mounting brackets.
  4. Install the new catalytic converter, ensuring proper alignment.
  5. Torque the bolts to the manufacturer's specifications.
  6. Reattach the exhaust pipes and ensure they are secure.

4. Reset the Engine Control Module (ECM)

• Sub-steps:
  1. Reconnect the battery.
  2. Use an OBD-II scanner to clear the P0420 code from the ECM.
  3. Start the vehicle and let it idle for a few minutes.