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

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors (usually near the exhaust manifold and catalytic converter).
  2. Disconnect the electrical connectors from both sensors.
  3. Using a socket wrench, remove the oxygen sensors from their positions.
  4. Install the new oxygen sensors in the same locations and torque to manufacturer's specifications (typically around 30 ft-lbs).
  5. Reconnect the electrical connectors securely.

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

• Sub-steps:
  1. If the catalytic converter is suspected to be faulty after testing, prepare to replace it.
  2. Raise the vehicle using a jack and secure it with jack stands.
  3. Locate the catalytic converter and remove any heat shields if applicable.
  4. Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe, noting any gaskets or seals.
  5. Remove the old catalytic converter and inspect the exhaust system for issues (e.g., rust, damage).
  6. Install the new catalytic converter, ensuring to use new gaskets and torque the bolts to specifications (usually around 25-35 ft-lbs).
  7. Reattach any heat shields removed earlier.

4. Clear Codes and Reconnect Battery

• Sub-steps:
  1. Reconnect the battery negative terminal.
  2. Use the OBD-II scanner to clear the P0420 code and any other related codes.