how to fix the P0420 code in my Honda Accord 9th Generation (2013-2017)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the vehicle battery to prevent electrical shorts.
• Allow the engine to cool before performing any work on exhaust components.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream oxygen sensor using an O2 sensor socket.
  • Sub-step: Disconnect the electrical connector.
  • Sub-step: Install the new oxygen sensor and torque to manufacturer specifications (typically around 30 lb-ft).
• Repeat the process for the downstream oxygen sensor if it has been determined faulty.

3. Inspect and Replace Catalytic Converter (if needed)

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter (if necessary).
• Raise the vehicle securely on jack stands.
• Locate the catalytic converter and inspect for damage.
  • Sub-step: If damaged, remove the existing catalytic converter by unbolting it from the exhaust system.
  • Sub-step: Install the new catalytic converter and ensure all connections are tight.
  • Sub-step: Use exhaust sealant on joints if applicable.

4. Clear Codes and Test

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code.
• Start the engine and allow it to reach operating temperature.