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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to ensure safety during repairs.
• Allow the vehicle to cool before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set
• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Disconnect the electrical connectors from both oxygen sensors.
  3. Use the O2 sensor socket to unscrew and remove the sensors.
  4. Install the new oxygen sensors in reverse order, ensuring they are tightened to manufacturer specifications (typically around 30 ft-lbs).
  5. Reconnect the electrical connectors.

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

• Tools Required: Socket set, torque wrench, exhaust gasket
• Sub-steps:
  1. Unbolt the exhaust pipe from the catalytic converter using a socket set.
  2. Remove any heat shields or brackets that may obstruct access.
  3. Inspect the catalytic converter for physical damage or excessive soot buildup.
  4. If replacement is necessary, install the new catalytic converter with a new gasket, tightening bolts to manufacturer specifications.
  5. Reinstall any removed components such as heat shields.

4. Repair Exhaust Leaks

• Tools Required: Exhaust sealant, wire brush
• Sub-steps:
  1. Identify any leaks in the exhaust system by visually inspecting joints and connections.
  2. Clean the area around any leaks with a wire brush to ensure proper adhesion of sealant.
  3. Apply exhaust sealant to any gaps or cracks and allow it to cure as per the manufacturer's instructions.

5. Reconnect Battery and Clear Codes

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