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

Solution

1. Preparation

• Gather tools and parts necessary for the repair.
• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, oxygen sensor socket, and safety glasses.
• Safety Warnings: Disconnect the battery before working on electrical systems. Allow the engine to cool before working on exhaust components.

2. Inspect and Replace Oxygen Sensors

• Step 1: Remove the negative battery terminal to prevent electrical shorts.
• Step 2: Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
• Step 3: Use an oxygen sensor socket to unscrew the sensors from their locations.
• Step 4: Install the new oxygen sensors by threading them in by hand, then tighten them to the manufacturer's specifications (usually around 30-35 lb-ft).
• Step 5: Reconnect the electrical connectors to the new sensors.

3. Inspect and Replace the Catalytic Converter

• Step 1: Remove any heat shields or brackets securing the catalytic converter.
• Step 2: Unbolt the catalytic converter from the exhaust system using a socket set.
• Step 3: Inspect the exhaust pipes for any signs of damage or blockage.
• Step 4: Install the new catalytic converter, ensuring a proper fit and alignment.
• Step 5: Tighten all bolts to the manufacturer's torque specifications (usually around 30-40 lb-ft).
• Step 6: Reinstall any heat shields or brackets that were removed.

4. Clear Codes and Test Drive

• Step 1: Reconnect the negative battery terminal.
• Step 2: Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
• Step 3: Start the engine and allow it to reach operating temperature.
• Step 4: Perform a test drive of at least 20 minutes under various driving conditions to monitor for any reoccurrence of the code.