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

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, OBD-II scanner.
• Remove the upstream (pre-catalytic) oxygen sensor:
  1. Locate the upstream O2 sensor near the exhaust manifold.
  2. Use the O2 sensor socket to unscrew the sensor.
  3. Inspect for any signs of damage or corrosion.
  4. Install the new O2 sensor, applying anti-seize compound to the threads.
• Repeat for the downstream (post-catalytic) oxygen sensor.

3. Check and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if needed).
• Inspect the catalytic converter:
  1. Look for cracks or signs of impact damage.
  2. Check for excessive heat discoloration.
• If replacement is necessary:
  1. Unbolt the catalytic converter from the exhaust system.
  2. Remove any heat shields if applicable.
  3. Install the new catalytic converter, ensuring proper alignment.
  4. Torque the bolts to the manufacturer’s specifications.

4. Clear Codes and Test

• Use the OBD-II scanner to clear the P0420 code from the vehicle’s memory.
• Reconnect the negative battery terminal.
• Start the engine and allow it to reach operating temperature.