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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, jack and jack stands, safety glasses, gloves.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors connected to the exhaust system.
  2. Unplug the electrical connectors from both sensors.
  3. Use a socket wrench to remove the sensors from the exhaust pipes.
  4. Install new oxygen sensors, ensuring they are torqued to manufacturer specifications (typically around 30 ft-lbs).
  5. Reconnect the electrical connectors securely.

3. Inspect and Replace the Catalytic Converter

• Sub-steps:
  1. Support the vehicle using jack stands and remove the exhaust system components as needed to access the catalytic converter.
  2. Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe, ensuring to collect any gaskets for replacement.
  3. Inspect the old catalytic converter for damage or blockage.
  4. Install the new catalytic converter, ensuring proper alignment and reusing or replacing gaskets as necessary.
  5. Torque the bolts to manufacturer specifications (usually around 30-40 ft-lbs for exhaust bolts).

4. Reconnect Battery and Clear Codes

• Sub-steps:
  1. Reconnect the battery terminals securely.
  2. Use the OBD-II scanner to clear the P0420 code from the ECU.
  3. Start the vehicle and allow it to reach operating temperature.