My 91 honda accord Ex can be kept on all day or driven under 40 miles per hour but it seems as soon as i go over 50 miles per hour after like 10 minutes the check engine light turns on my car is running perfectly no symptoms whatsoever engine runs fine even when the light turns on. My car has about 90,000 miles the transmission and engine are in very good condition maintainance is performed regularly but i want to find out whats triggering the light before it can possibly become a serious problem. Auto Zone doesnt tests cars after 97 and i would rather fix it myself than get played by some other mechanic. What are some probable causes any information will be greatly appreciated.

Thank U for your time.

You need to run the codes..if autozone wont do it, then you can do it yourself quite easily.
Here is how:
http://www.hondapitstop.com/accord/technotes1/engine/error_codes/error_codes.html

Thank you your advice it worked the ecu marking fuel pump 43 which i had replaced a few days ago but the memory stored the code which i thought i had reset because the fuse box tricked me instead i should have pulled the 7.5 in the corner of the fuse box which i did and the check engine light is gone. That light was driving me crazy your advice was the shit your the man.