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

Solution

1. Preparation

• Gather tools and parts required for repairs.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Repair Exhaust Leaks

• Tools Required: Socket set, exhaust pipe sealant.
• Inspect the exhaust system for leaks.
• If leaks are found, repair or replace damaged sections as necessary. Use exhaust pipe sealant for minor gaps.

3. Replace Faulty Oxygen Sensors

• Tools Required: O2 sensor socket, wrench, torque wrench.
• If voltage readings from the oxygen sensors are outside specifications, replace the faulty sensors:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Disconnect the electrical connector from the sensor.
  3. Use the O2 sensor socket to unscrew the sensor from the exhaust pipe.
  4. Install the new oxygen sensor and torque to manufacturer's specifications (usually around 30 lb-ft).
  5. Reconnect the electrical connector.

4. Replace the Catalytic Converter (if necessary)

• Tools Required: Socket set, jack stands, cutting tool (if required).
• If the catalytic converter is determined to be faulty:
  1. Raise the vehicle safely on jack stands.
  2. Remove the exhaust system components connected to the catalytic converter using the socket set.
  3. If necessary, cut the old converter out, ensuring not to damage surrounding pipes.
  4. Install the new catalytic converter, ensuring proper alignment and sealing.
  5. Reattach all exhaust components and securely tighten all bolts.

5. Reset the ECU

• Tools Required: OBD-II scanner.
• After repairs are complete, use the OBD-II scanner to clear the P0420 code from the ECU.