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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety during repairs.
• Raise the vehicle using jack stands to access the exhaust system.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use an oxygen sensor socket to remove the sensors from the exhaust manifold and catalytic converter.
  4. Install new oxygen sensors (ensure they are compatible with the model).
  5. Torque the new sensors to manufacturer specifications (usually around 30-40 ft-lbs).
  6. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  1. Remove the flange bolts securing the catalytic converter to the exhaust system using a socket set.
  2. Carefully detach the catalytic converter from the exhaust system.
  3. Inspect the old catalytic converter for signs of damage or clogging.
  4. Install a new catalytic converter, ensuring the correct orientation.
  5. Torque the flange bolts to manufacturer specifications (typically around 30-40 ft-lbs).
  6. Reconnect any heat shields or other components removed during the process.

4. Reconnect Battery and Test

• Sub-steps:
  1. Reconnect the battery terminals.
  2. Start the engine and allow it to reach operating temperature.
  3. Monitor for any error codes using the OBD-II scanner to confirm repair success.

Tools Required:

• OBD-II scanner
• Socket set
• Oxygen sensor socket
• Torque wrench
• Multimeter
• Thermocouple (optional)

Parts Required:

• Upstream oxygen sensor
• Downstream oxygen sensor
• Catalytic converter (if needed)

Estimated Repair Time: 2-4 hours

Safety Warnings:

• Disconnect the battery before working on electrical systems.
• Allow the exhaust system to cool before handling any components to avoid burns.