my Toyota Corolla E140 (2006-2013) has a persistent check engine light, what now

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Disconnect the battery to ensure safety while working on electrical components.

2. Address Fault Codes

• Sub-step 1: Using the OBD-II scanner, retrieve and document the specific error codes.
• Sub-step 2: Research each code to understand the underlying issues (e.g., P0420 for catalytic converter efficiency).

3. Replace Faulty Components

• Sub-step 1: If codes indicate a faulty oxygen sensor, remove the old sensor using an oxygen sensor socket.
• Sub-step 2: Install the new sensor and torque it to manufacturer specifications (typically around 30 ft-lbs).
• Sub-step 3: If the issue is related to the catalytic converter, consult a professional for replacement, as it may require welding or specific tools.

4. Reset Check Engine Light

• Sub-step 1: Reconnect the battery terminals after repairs.
• Sub-step 2: Use the OBD-II scanner to clear the trouble codes and reset the check engine light.

5. Final Inspection

• Sub-step 1: Start the engine and monitor for any immediate warning lights.
• Sub-step 2: Conduct a test drive to ensure the check engine light does not reappear.