how to identify and fix P0420 code in Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery cable to prevent electrical shock.

2. Inspect and Replace Oxygen Sensors

• Sub-step 1: Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
• Sub-step 2: Disconnect the electrical connectors from both sensors.
• Sub-step 3: Use an oxygen sensor socket to remove the sensors from their respective locations.
• Sub-step 4: Install new oxygen sensors (ensure they are compatible with the vehicle model).
• Sub-step 5: Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-step 1: Visually inspect the catalytic converter for any signs of damage or blockage.
• Sub-step 2: If replacement is needed, remove the bolts securing the catalytic converter to the exhaust system using a socket set.
• Sub-step 3: Carefully detach the catalytic converter and inspect the mating surfaces for any debris.
• Sub-step 4: Install a new catalytic converter, applying new gaskets as necessary.
• Sub-step 5: Tighten the bolts to the manufacturer’s specified torque settings (typically 30-35 lb-ft).

4. Clear Codes and Test

• Sub-step 1: Reconnect the negative battery cable.
• Sub-step 2: Use the OBD-II scanner to clear the P0420 code.
• Sub-step 3: Start the engine and allow it to reach operating temperature.
• Sub-step 4: Take the vehicle for a test drive to ensure the check engine light does not reappear.