98 contour computer code

I have a 98 contour that the service engine light came on. When I stopped at autozone to have them read the code and tell me what was wrong they said because the code was 1131 they could not tell me exaxtly what was wrong. What does code p 1131 indocates is wrong. The engine service light went off shortly after it came on. The car was and contin ued to run fine. thanks for the help

Possibly a loose fuel cap or door.  It will reset itself after a day or two.  Or reset itself after you start and stop the car a few times.