I have a 1993 ford taurus 3.8L V6 automatic. When the check engine light comes on is that telling you that a sensor is bad? Is that the only purpose of the check engine light?
The check engine light is there to alert you to a developing problem. It is an early warning system. The problem could be a sensor or it could be something else. Take the car to a mechanic or an auto parts store and have the computer trouble codes read. The codes should give you some idea where the problem is.
Ignoring the light will lead to larger, more expensive problems.
usually an oxygen sensor. Can be cheap to several hundred dollars.
That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code not just their translation into English and post it back here. It likely will have a format like P1234.