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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is safely elevated on jack stands if needed.
• Disconnect the battery to prevent electrical shocks.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench, multimeter
• Remove the upstream oxygen sensor from the exhaust manifold:
  1. Disconnect the electrical connector from the sensor.
  2. Use the O2 sensor socket to remove the sensor from the exhaust manifold.
• Test the new sensor before installation using a multimeter to ensure it functions properly.
• Install the new upstream oxygen sensor and reconnect the electrical connector.
• Repeat this process for the downstream oxygen sensor if necessary.

3. Inspect and Replace the Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust hanger removal tool
• Remove the exhaust pipe connected to the catalytic converter:
  1. Loosen and remove the bolts or nuts securing the exhaust pipe to the catalytic converter.
  2. Use the exhaust hanger removal tool to detach any hangers.
• Remove the old catalytic converter from the vehicle.
• Install the new catalytic converter by reversing the removal steps:
  1. Ensure all gaskets are in good condition; replace if necessary.
  2. Torque the bolts to the manufacturer’s specifications (usually around 30-40 lb-ft, but check specific guidelines).

4. Reset the Engine Control Module (ECM)

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code from the ECM.
• Start the engine and let it run for a few minutes to monitor for any new codes.