how to fix P0420 code in Ford Mustang S650 (2024-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is on a level surface and securely supported.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor wrench, socket set, torque wrench.
• Remove the upstream oxygen sensor:
  • Locate the sensor on the exhaust manifold or header.
  • Use the O2 sensor wrench to unscrew the sensor.
• Install the new upstream oxygen sensor:
  • Apply anti-seize compound to the threads.
  • Torque to manufacturer specifications (typically around 30-40 lb-ft).
• Repeat for the downstream oxygen sensor if it is faulty.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, cutting tool (if necessary), gaskets.
• Disconnect the exhaust system:
  • Loosen and remove the bolts securing the catalytic converter to the exhaust manifold and the exhaust pipe.
• Remove the old catalytic converter.
• Install the new catalytic converter:
  • Align the new converter with the exhaust system.
  • Use new gaskets as needed and torque bolts to manufacturer specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals securely.
• Use the OBD-II scanner to clear the P0420 code.