how to fix P0420 code on my Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Gather necessary tools and parts before starting the repair.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

1. Remove the upstream oxygen sensor:
   • Locate the sensor, typically positioned before the catalytic converter.
   • Use an oxygen sensor socket or wrench to unscrew the sensor.
   • Disconnect the wiring harness from the sensor.
2. Install the new upstream oxygen sensor:
   • Apply anti-seize compound to the threads of the new sensor to prevent seizing.
   • Screw in the new sensor and tighten to the manufacturer's specified torque (usually around 30 ft-lbs).
   • Reconnect the wiring harness.
3. Repeat the process for the downstream oxygen sensor, if necessary.

3. Inspect and Replace the Catalytic Converter

1. Remove the catalytic converter:
   • Loosen and remove any bolts or clamps securing the catalytic converter to the exhaust system.
   • Carefully detach the converter from the exhaust pipe and any remaining connections.
2. Install the new catalytic converter:
   • Ensure that the new converter is compatible with the vehicle.
   • Position the new converter and secure it using new gaskets and bolts as required.
   • Tighten all connections to the specified torque.

4. Reconnect Battery and Clear Codes

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