Toyota Corolla E170 (2013-2019) P0420 code what does it indicate

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

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream and downstream oxygen sensors using the O2 sensor socket.
• Inspect the sensors for carbon buildup or damage.
• If damaged, replace with new sensors.
• Torque the new sensors to the manufacturer's specification (typically around 30 lb-ft).

3. Inspect and Replace Catalytic Converter (if needed)

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter or saw, welding equipment (if welding is necessary).
• Raise the vehicle and support with jack stands.
• Remove the exhaust pipes connected to the catalytic converter by loosening the clamps or removing bolts.
• Inspect the catalytic converter for any signs of physical damage or blockage.
• If replacement is necessary, install the new catalytic converter, ensuring proper alignment.
• Reattach exhaust pipes and secure with clamps or bolts.

4. Reset the Engine Control Module (ECM)

• Reconnect the battery terminals.
• Use an OBD-II scanner to clear the P0420 code from the ECM.
• Start the engine and let it idle for a few minutes.