how to fix P0420 code in Honda CR-V Sixth Generation (2023-present)

Solution

1. Preparation

• Ensure the vehicle is on a flat surface and the parking brake is engaged.
• Disconnect the battery to prevent any electrical issues.
• Gather necessary tools and parts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: OBD-II scanner, socket set, torque wrench
• Remove the upstream (pre-catalytic) oxygen sensor:
  • Unplug the electrical connector.
  • Use a socket wrench to remove the sensor from the exhaust manifold.
• Inspect the sensor for corrosion or damage.
• If faulty, replace with a new sensor, ensuring it is properly torqued to manufacturer specifications (typically around 30-35 ft-lbs).
• Repeat the process for the downstream (post-catalytic) oxygen sensor if necessary.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, cutting tool (if necessary), exhaust gasket
• Remove the catalytic converter:
  • Unbolt the catalytic converter from the exhaust system, ensuring all bolts are accounted for.
  • If the converter is welded in, use a cutting tool to remove it carefully.
• Inspect the new catalytic converter for fitment and damage before installation.
• Install the new catalytic converter, ensuring it is secured properly with bolts and gaskets to prevent leaks.
• Torque bolts to the manufacturer’s specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals securely.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
• Start the engine and let it idle for a few minutes to allow the system to recalibrate.