how to fix Toyota Corolla E170 (2013-2019) P0420 code for catalytic converter

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, safety glasses, gloves.
• Ensure the vehicle is parked on a level surface, the engine is cool, and the keys are removed from the ignition.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Disconnect the negative battery terminal to prevent electrical shorts.
  2. Locate the upstream (pre-catalytic) oxygen sensor, usually found on the exhaust manifold or just before the catalytic converter.
  3. Remove the oxygen sensor using a socket or wrench.
  4. Install the new oxygen sensor and torque it to the manufacturer's specification (typically around 30-45 ft-lbs).
  5. Repeat the above steps for the downstream (post-catalytic) oxygen sensor.

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  1. Remove the heat shield if present, using the appropriate socket.
  2. Unbolt the catalytic converter from the exhaust system, paying attention to the gasket condition.
  3. Inspect the old catalytic converter for signs of clogging or physical damage.
  4. Install the new catalytic converter with a new gasket, ensuring proper alignment.
  5. Torque the bolts to manufacturer specifications (usually around 30-40 ft-lbs).

4. Clear Trouble Codes

• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Use an OBD-II scanner to clear any trouble codes from the system.
  3. Start the engine and allow it to reach operating temperature.