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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Locate the O2 Sensors: Find the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Remove the O2 Sensors:
   • Use an oxygen sensor socket or wrench.
   • Carefully unscrew the sensors and disconnect the wiring harness.
3. Install New O2 Sensors:
   • Apply anti-seize compound to the threads of the new sensors.
   • Screw in the new sensors and reconnect the wiring harness.
   • Torque the sensors to the manufacturer's specifications (typically around 30 lb-ft).

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

1. Inspect the Catalytic Converter: Look for physical damage or clogging.
2. Remove the Catalytic Converter:
   • Unbolt the exhaust pipes connected to the catalytic converter.
   • Use a wrench or socket set to remove bolts.
3. Install New Catalytic Converter:
   • Position the new converter in place.
   • Bolt it to the exhaust pipes and ensure all connections are secure.
   • Torque the bolts to the manufacturer's specifications.

4. Reset the Engine Control Module (ECM)

1. Reconnect the Battery: After completing repairs, reconnect the battery terminals.
2. Clear the Codes: Use an OBD-II scanner to clear the P0420 code from the ECM.