how to fix P0420 code on Ram 1500 DT (2019-Present)

Solution

1. Preparation

• Gather tools and materials needed.
• Disconnect the battery to prevent electrical shorts.
• Ensure the vehicle is parked on a level surface and secured with wheel chocks.

2. Inspect and Replace O2 Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench, multimeter.
• Remove the upstream oxygen sensor using the O2 sensor socket.
• Install the new upstream oxygen sensor and torque it to the manufacturer’s specifications (typically around 30 ft-lbs).
• Repeat for the downstream oxygen sensor if needed.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, exhaust pipe cutter, gaskets, torque wrench.
• Remove the exhaust pipe bolts connecting to the catalytic converter.
• Cut the exhaust pipe if necessary and remove the old catalytic converter.
• Clean the mounting surfaces where the new catalytic converter will attach.
• Install the new catalytic converter, ensuring proper alignment.
• Torque the bolts to the manufacturer's specifications (usually around 30-40 ft-lbs).
• Reconnect any exhaust hangers and check for proper alignment.

4. Reset the OBD-II System

• Reconnect the battery.
• Use an OBD-II scanner to clear the P0420 code from the vehicle's computer.
• Ensure all connections are secure and the vehicle is ready for testing.