how to fix P0420 code on my Toyota Tacoma N300 (2016-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to avoid electrical shorts.
• Allow the vehicle to cool down if the engine has been running.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Sub-steps:
  1. Locate the front and rear oxygen sensors on the exhaust system.
  2. Use the O2 sensor socket to carefully unscrew the sensors from their mounting points.
  3. Install new oxygen sensors by hand-tightening them first, then torque to the manufacturer's specifications (usually 30 lb-ft).
  4. 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, torque wrench.
• Sub-steps:
  1. Raise the vehicle securely using jack stands and remove any heat shields that may cover the catalytic converter.
  2. Disconnect the exhaust pipes from the catalytic converter using the socket set.
  3. Remove the old catalytic converter, ensuring to note the orientation and any gaskets.
  4. Install the new catalytic converter, ensuring proper alignment and replacing gaskets as necessary.
  5. Reconnect the exhaust system and tighten all bolts to the manufacturer's torque specifications.

4. Check for Exhaust Leaks

• Tools Required: Smoke machine or soapy water solution.
• Sub-steps:
  1. Run the engine and use a smoke machine around the exhaust system to detect leaks.
  2. If using soapy water, apply it to joints and seams to look for bubbling indicating a leak.
  3. Repair any leaks found by tightening connections or replacing damaged sections.

5. Reset the OBD-II System

• Tools Required: OBD-II scanner.
• Sub-steps:
  1. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
  2. Reconnect the battery.