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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the battery to prevent any electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Locate the upstream and downstream oxygen sensors in the exhaust system.
• Use the O2 sensor socket to remove the upstream oxygen sensor.
• Install the new upstream oxygen sensor, tightening it to the manufacturer's specified torque (typically around 30-40 lb-ft).
• Repeat the process for the downstream oxygen sensor if it appears faulty or if the code persists.

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

• Tools Required: Socket set, cutting tool (if needed), torque wrench.
• Remove any heat shields or brackets securing the catalytic converter.
• Unbolt the catalytic converter from the exhaust manifold and the mid-pipe, taking care to note the position and orientation.
• Inspect the catalytic converter for physical damage or clogging. If damaged, replace it with a new unit, ensuring it meets OEM specifications.
• Reinstall the catalytic converter, using new gaskets or seals as necessary, and tighten all bolts to the specified torque (typically around 25-30 lb-ft).

4. Reset the Engine Control Module (ECM)

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code from the ECM.
• Start the engine and allow it to reach operating temperature.