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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface, and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors on the exhaust system.
  2. Disconnect the electrical connectors from both sensors.
  3. Use the O2 sensor socket and ratchet to carefully remove the sensors from the exhaust pipe.
  4. Install the new sensors by threading them into the exhaust pipe and tightening them to the manufacturer’s torque specification (typically around 30 lb-ft).
  5. Reconnect the electrical connectors to the new sensors.

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

• Tools Required: Socket set, jack stands, exhaust pipe cutter, gasket scraper, high-temperature exhaust gasket sealant.
• Sub-steps:
  1. Raise the vehicle using jack stands and remove any underbody shields that may obstruct access to the catalytic converter.
  2. Disconnect the exhaust pipes from the catalytic converter using a socket set. Cut the exhaust pipe if necessary.
  3. Remove the catalytic converter and inspect for physical damage or clogging.
  4. Install the new catalytic converter, ensuring proper alignment with the exhaust pipes.
  5. Use high-temperature exhaust gasket sealant on the joints and tighten the connections securely.

4. Clear Codes and Test

• Tools Required: OBD-II scanner.
• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
  3. Perform a test drive under various conditions to ensure the code does not reappear.