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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety while working on the electrical system.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, socket set, torque wrench.
• Remove the upstream oxygen sensor by using the O2 sensor socket.
• Check the wiring and connector for damage, and replace if necessary.
• Install a new oxygen sensor and torque to manufacturer specifications (typically around 30 lb-ft).
• Repeat for the downstream oxygen sensor if necessary.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust hanger removal tool.
• Raise the vehicle securely using jack stands.
• Remove any heat shields, if present, to access the catalytic converter.
• Disconnect the exhaust pipes from the catalytic converter, ensuring to retain any gaskets.
• Remove the catalytic converter from its mounts and inspect for damage.
• Install the new catalytic converter, ensuring proper alignment and tightness. Torque bolts to manufacturer specifications.
• Reattach any heat shields and reconnect the exhaust pipes.

4. Clear Error Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.

5. Final Inspection

• Start the engine and allow it to reach operating temperature.
• Check for leaks around the exhaust joints and ensure all sensors are functioning correctly.