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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to avoid electrical shorts.
• Ensure the vehicle is parked on a level surface and securely raised with jack stands.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Locate the upstream and downstream oxygen sensors.
• Unplug the electrical connectors from both sensors.
• Use the O2 sensor socket to remove the upstream sensor first, then the downstream sensor.
• Install the new sensors, hand-tightening first and then using a torque wrench to tighten to manufacturer specifications (typically around 30 lb-ft).
• Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, cutting tool (if needed), exhaust sealant
• Disconnect the exhaust pipes connected to the catalytic converter using the socket set.
• Remove any heat shields if present and detach the catalytic converter.
• Inspect the new catalytic converter for any damage before installation.
• Install the new catalytic converter, ensuring proper alignment.
• Reattach the exhaust pipes and secure with new gaskets and bolts, tightening to manufacturer specifications.

4. Reset the Engine Control Module (ECM)

• Reconnect the battery.
• Use an OBD-II scanner to clear the P0420 code from the ECM.
• Ensure all connections are secure and components are properly installed.