how to fix P0420 code in Honda CR-V Fifth Generation (2017-2022)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to ensure safety during the repair.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, and torque wrench.
• Instructions:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use the O2 sensor socket to remove the sensors from the exhaust manifold and catalytic converter.
  4. Install the new oxygen sensors by threading them into place and tightening to the manufacturer's specified torque (usually around 30 lb-ft).
  5. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust hanger removal tool.
• Instructions:
  1. Raise the vehicle securely using jack stands.
  2. Locate the catalytic converter and inspect for damage or excessive carbon buildup.
  3. If replacement is needed, remove the exhaust pipes connected to the catalytic converter by loosening the clamps and bolts.
  4. Remove any exhaust hangers using the removal tool.
  5. Install the new catalytic converter, ensuring it is properly aligned with the exhaust system.
  6. Reattach the exhaust pipes and torque the bolts to manufacturer specifications.
  7. Reinstall the exhaust hangers.

4. Reset the Engine Control Module (ECM)

• Tools Required: OBD-II scanner.
• Instructions:
  1. Reconnect the negative battery terminal.
  2. Use the OBD-II scanner to clear the P0420 code from the ECM.
  3. Start the engine and allow it to idle for a few minutes.