how to fix the check engine light on my Toyota Corolla E210 (2019-2024)

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Disconnect the negative battery terminal to ensure safety while working on the vehicle.

2. Error Code Resolution

• a. Retrieve and record error codes using the OBD-II scanner.
• b. Research the codes to determine the specific issues (e.g., P0420 for catalyst efficiency).
• c. Address the specific issue indicated by the codes; for example, if the code indicates an oxygen sensor failure, proceed to replace the sensor.

3. Replace Faulty Components

• a. For a faulty gas cap: Remove the old gas cap and install a new OEM gas cap, ensuring it's tightened properly to avoid leaks.
• b. For a faulty oxygen sensor:
  • Locate the sensor (typically upstream or downstream of the catalytic converter).
  • Unplug the electrical connector and remove the sensor using a wrench.
  • Install the new sensor, applying anti-seize compound to the threads if recommended.
  • Reconnect the electrical connector.

4. Clear Error Codes

• Use the OBD-II scanner to clear the error codes after repairs have been made.
• Reconnect the negative battery terminal.

5. Finalize and Test

• Start the engine and allow it to reach operating temperature.
• Monitor for the check engine light to remain off during idle and initial driving.