Here's what you should do:
1. Get the Diagnostic Trouble Code (DTC): This is the most important step. The check engine light is triggered by a stored code that identifies the potential problem. You have a few options:
* OBD-II Scanner: The cheapest and easiest way is to buy a relatively inexpensive OBD-II scanner from an auto parts store (like AutoZone, Advance Auto Parts, or O'Reilly's). These plug into your car's OBD-II port (usually under the dashboard) and read the code(s). The scanner will give you a code number (like P0171, P0420, etc.). Write this down!
* Auto Parts Store Scan: Many auto parts stores will scan your car for free. They can tell you the code and often give you a possible cause.
* Mechanic: A mechanic will have professional diagnostic equipment and can accurately pinpoint the problem.
2. Research the DTC: Once you have the code(s), search online (e.g., Google the code plus "Chevrolet Impala SS") to find out what it means. Websites and forums dedicated to car repair often have detailed information about specific codes and their likely causes.
3. Possible Causes (General, Requires DTC for specifics): Without knowing the code, some common causes for intermittent check engine lights include:
* Loose or failing gas cap: This is a frequent culprit, and a simple fix. Make sure your gas cap is securely tightened.
* Oxygen sensor: These sensors monitor the exhaust and can cause an intermittent light if they're starting to fail.
* Mass airflow sensor (MAF): This sensor measures the air entering the engine. A dirty or failing MAF sensor can cause performance issues and trigger the light.
* Other sensors: Various other sensors (temperature, coolant, etc.) can also trigger the light if they malfunction.
* Intermittent electrical connection: A loose wire or connector somewhere in the engine's electrical system could be the problem.
Don't delay: While the car might seem fine now, the underlying problem could worsen, potentially causing damage to your engine or catalytic converter. Getting the code and addressing the issue promptly is the best way to avoid more significant repairs later.
