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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the vehicle's battery to prevent electrical shorts.
• Allow the exhaust system to cool down before working on it.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream and downstream oxygen sensors using the O2 sensor socket.
• Inspect the sensors for contamination or damage.
• Replace any faulty oxygen sensors with new, OEM-quality sensors.
• Torque the new sensors to the manufacturer's specification (usually around 30 ft-lbs).

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, jack stands, exhaust gasket, torque wrench
• Raise the vehicle securely using jack stands.
• Disconnect the exhaust pipes connected to the catalytic converter using a socket set.
• Remove the catalytic converter from its mounting brackets and any additional supports.
• Install the new catalytic converter, ensuring all gaskets are in good condition.
• Torque the exhaust connections to the manufacturer's specification (refer to repair manual).

4. Clear Codes and Test

• Reconnect the vehicle's battery.
• Use the OBD-II scanner to clear the P0420 code.
• Start the vehicle and let it reach operating temperature, monitoring for any reoccurrence of the code.