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

Solution

1. Preparation

• Gather tools and parts needed.
• Ensure the vehicle is parked on a flat surface, and the engine is cool.
• Disconnect the battery to ensure safety while working on the electrical components.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream (pre-catalytic) oxygen sensor:
  1. Disconnect the electrical connector from the sensor.
  2. Use the O2 sensor socket to unscrew the sensor from the exhaust manifold.
  3. Install the new sensor and torque it to the manufacturer's specifications (usually around 30 lb-ft).
  4. Reconnect the electrical connector.
• Repeat the process for the downstream (post-catalytic) oxygen sensor if necessary.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, cutting tool (if necessary), exhaust gasket
• If the catalytic converter is damaged:
  1. Disconnect any exhaust hangers and remove the bolts securing the catalytic converter to the exhaust system.
  2. If necessary, cut the pipes using a cutting tool.
  3. Install the new catalytic converter, ensuring proper alignment with exhaust pipes.
  4. Secure it with bolts and replace any gaskets as needed, torquing to manufacturer specifications.

4. Reset the Engine Control Module (ECM)

• Tools Required: OBD-II scanner
• Use the scanner to clear the P0420 code from the ECM.
• Reconnect the battery if it was disconnected.