my Honda Civic 11th Generation (2022-Present) has a check engine light with P0420 code, what does it...

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: Oxygen sensor socket, ratchet, extensions, torque wrench.
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use the oxygen sensor socket to remove the sensors from the exhaust system.
  4. Install the new oxygen sensors and tighten to specifications (generally 30-40 ft-lbs).
  5. Reconnect the electrical connectors.

3. Inspect and Replace the Catalytic Converter (if necessary)

• Tools Required: Wrench set, jack and jack stands, exhaust pipe cutter, gasket scraper.
• Sub-steps:
  1. Raise the vehicle and securely support it on jack stands.
  2. Remove any heat shields if applicable.
  3. Disconnect the exhaust pipes from the catalytic converter using a wrench or exhaust pipe cutter, if necessary.
  4. Remove the catalytic converter from its mounting points.
  5. Clean the mounting surfaces to ensure a good seal for the new converter.
  6. Install the new catalytic converter and secure it in place.
  7. Reconnect the exhaust pipes and any heat shields, ensuring all connections are tight.

4. Reset the Engine Control Module (ECM)

• Tools Required: OBD-II scanner.
• Sub-steps:
  1. Use the OBD-II scanner to clear the trouble codes from the ECM.
  2. Disconnect the battery for about 15 minutes to reset the system (optional).