What does a check engine light mean?

From Faq

Hey Guys, from personal experiences I have had with the check engine light coming on was due to faulty Oxygen Sensors. That is just one of several explanations why the light is coming on. Typically this light comes on when there is an exhaust and/or oxygen malfunction that is communicating with the onboard computer sensor alerting you to these problems. If you are having these problems, try changing out the Oxygen Sensors first (there are two and be forwarned, they are not cheap), then make sure all air ducts leading into the engine compartment are not blocking air from reaching the engine. Hope this helps some!