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

Solution

1. Preparation

• Gather necessary tools and ensure you have a clean workspace.
• Disconnect the battery to avoid any electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use the O2 sensor socket to remove the sensors from the exhaust system.
  4. Install the new sensors and torque them to manufacturer specifications (typically around 30-40 lb-ft).
  5. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter or saw, high-temperature exhaust sealant.
• Sub-steps:
  1. Raise the vehicle using a jack and secure it with jack stands.
  2. Remove any heat shields if present.
  3. Use the exhaust pipe cutter or saw to cut the old catalytic converter from the exhaust system.
  4. Clean the mating surfaces on the exhaust pipes.
  5. Install the new catalytic converter using high-temperature exhaust sealant and torque to specifications.
  6. Reinstall any heat shields.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0420 code from the engine control module.