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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent any electrical shorts during the repair.
• Allow the engine to cool completely before starting.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use an O2 sensor socket to remove the sensors from the exhaust manifold and the catalytic converter.
  4. Install the new oxygen sensors, ensuring to apply anti-seize compound on the threads.
  5. Tighten to manufacturer specifications (usually around 30 lb-ft).

3. Inspect and Repair Exhaust System

• Sub-steps:
  1. Visually inspect the exhaust for any cracks, holes, or loose connections.
  2. Repair any leaks using exhaust tape, clamps, or replace sections of the exhaust as necessary.
  3. Ensure all gaskets and seals are in good condition and replace if damaged.

4. Replace the Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove the bolts securing the catalytic converter to the exhaust system using a socket set.
  2. If applicable, disconnect any heat shields or mounting brackets.
  3. Remove the old catalytic converter and replace it with a new one, ensuring proper alignment with the exhaust system.
  4. Reinstall bolts and tighten to manufacturer specifications (usually around 30-35 lb-ft).

5. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0420 code and any other error codes present.