how to fix P0420 code on Ford Mustang S650 (2024-Present) catalytic converter

Solution

1. Preparation

• Gather all necessary tools and parts.
• Make sure the vehicle is on a level surface and securely raised using jack stands.
• Disconnect the battery to ensure safety while working on the vehicle electronics.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  • Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  • Disconnect the electrical connectors and use a socket wrench to remove the sensors.
  • Install the new oxygen sensors, ensuring they are properly torqued (typically around 30 lb-ft) and the connectors are securely attached.

3. Replace Catalytic Converter (if necessary)

• Sub-steps:
  • Remove any heat shields or brackets securing the catalytic converter.
  • Unbolt the catalytic converter from the exhaust system using a socket set (common sizes are 13mm or 15mm).
  • Install the new catalytic converter, ensuring correct orientation and fit.
  • Torque the bolts to the manufacturer's specifications (typically around 30-40 lb-ft).
  • Reinstall any heat shields or components removed during the process.

4. Reset the Engine Control Module (ECM)

• Sub-steps:
  • Reconnect the battery terminals.
  • Use the OBD-II scanner to clear the P0420 code and any other error codes stored in the system.

5. Final Inspection

• Sub-steps:
  • Start the engine and let it reach operating temperature.
  • Monitor for any exhaust leaks around the new catalytic converter and sensors.