how to fix P0420 code in my Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

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

2. Inspect and Repair Exhaust Leaks

• Tools Required: Wrench set, exhaust sealant, or replacement gaskets
• Inspect the exhaust pipes for cracks or holes.
• Tighten any loose connections or replace damaged gaskets.
• Apply exhaust sealant to minor leaks.

3. Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, ratchet wrench
• Locate the upstream and downstream oxygen sensors.
• Disconnect the electrical connectors.
• Use the O2 sensor socket to unscrew the sensors from the exhaust system.
• Install new sensors by screwing them in place and reconnecting the electrical connectors. Torque to manufacturer specifications (typically around 30 lb-ft).

4. Replace the Catalytic Converter (if necessary)

• Tools Required: Socket set, wrench set, exhaust pipe cutter, new catalytic converter
• Raise the vehicle safely using jack stands and remove the exhaust pipe leading to the catalytic converter.
• Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe.
• Install the new catalytic converter, ensuring proper alignment and sealing.
• Torque the bolts to manufacturer specifications (typically around 25 lb-ft).

5. Reconnect Battery and Clear Codes

• Reconnect the battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the system.