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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery cable to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, wrench set, multimeter
• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Using the O2 sensor socket, remove the sensors from the exhaust system.
  4. Test the new oxygen sensors with a multimeter to ensure they are functioning correctly.
  5. Install the new sensors by threading them into the exhaust system and securing them with the correct torque (typically around 30 lb-ft).
  6. Reconnect the electrical connectors for both sensors.

3. Inspect and Replace the Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust gasket sealant
• Sub-steps:
  1. Locate the catalytic converter in the exhaust system.
  2. Remove the bolts securing the catalytic converter to the exhaust manifold and the exhaust pipe using a socket set.
  3. Inspect the mounting surfaces for damage or corrosion.
  4. Remove the old gasket and clean the area where the new converter will be installed.
  5. Install the new catalytic converter along with a new gasket, ensuring proper alignment.
  6. Torque the bolts to the manufacturer specifications (typically around 40 lb-ft).
  7. Reconnect any heat shields or brackets that were removed.

4. Reset the OBD-II System

• Tools Required: OBD-II scanner
• Sub-steps:
  1. Connect the OBD-II scanner to the vehicle's diagnostic port.
  2. Clear the P0420 code from the ECM.
  3. Disconnect the scanner after the codes have been cleared.