how to clear the P0420 code on my Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent any electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench, penetrating oil.
• Inspect the upstream and downstream oxygen sensors for signs of wear or damage.
• If faulty, remove the oxygen sensors:
  • Apply penetrating oil to the threads and allow it to soak.
  • Use the O2 sensor socket and ratchet to carefully unscrew the sensors.
• Install new oxygen sensors:
  • Apply anti-seize compound to the threads of the new sensors.
  • Screw in the new sensors by hand, then tighten to the manufacturer's specified torque (typically 30 lb-ft).

3. Check and Repair Exhaust System

• Tools Required: Socket set, exhaust pipe cutter (if necessary), clamps, welding equipment (if applicable).
• Inspect the entire exhaust system for any leaks or damage.
• If a leak is found, repair or replace the damaged section:
  • Use an exhaust pipe cutter to remove damaged sections.
  • Install new exhaust pipe sections and securely clamp them.
  • Ensure all connections are tight and leak-free.

4. Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack and jack stands, torque wrench.
• If the catalytic converter is damaged or clogged:
  • Raise the vehicle using a jack and secure with jack stands.
  • Remove the bolts securing the catalytic converter to the exhaust manifold and exhaust pipe.
  • Carefully lower the old catalytic converter and install the new one in reverse order.
  • Tighten all bolts to the manufacturer's specified torque.

5. Clear the Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.