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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is turned off and parked on a level surface.
• Disconnect the battery to avoid electrical shorts.

2. Inspect and Test Oxygen Sensors

• Tools Required: OBD-II scanner, multimeter.
• Remove the upstream oxygen sensor (pre-catalytic converter) and inspect for damage.
• Use a multimeter to test the sensor's voltage output (should fluctuate between 0.1 to 0.9 volts).
• Repeat the same process for the downstream oxygen sensor.

3. Inspect Catalytic Converter

• Tools Required: Socket set, wrench.
• Remove the catalytic converter by loosening the bolts and disconnecting it from the exhaust system.
• Inspect the interior for signs of excessive soot or damage. A rattling sound may indicate broken substrate.
• If damaged, replace the catalytic converter with an OEM or quality aftermarket part.

4. Reinstall Components

• Tools Required: Torque wrench.
• Reinstall the catalytic converter, ensuring the bolts are torqued to the manufacturer's specifications.
• Reinstall the oxygen sensors, ensuring they are secured tightly.
• Reconnect the battery.

5. Clear Codes and Test Drive

• Use the OBD-II scanner to clear the P0420 code from the system.
• Start the engine and let it idle for a few minutes.
• Take the vehicle for a test drive to ensure the check engine light does not reappear.