If the Check Engine light has been on, the computer will have stored error codes. Given the conditions under which you have seen the light, the problem is most likely an emissions-related component such as an O2 sensor or the EGR system.
You will have to read them or have them read. There are hundreds of possible codes each with its own diagnostic.
Your 95 can be read with nothing more that a paper clip and your eyes.
Here is a site that tells you how:
http://dalidesign.com/hbook/eectest.html
Once you have extracted all codes, post them for assistance in deciphering them.
In many locations, chain stores such as AutoZone and Advance Auto parts will read your codes for free. If you take advantage of this service, WRITE DOWN THE CODES unless they can give you a printout.
Steve
