CEL light help please

[mitsukid124]

well yesterday i was driving from my friends birthday party to another friends house and i was kinda gettin on the throttle a little bit but nothin crazy, like in the 3 - 4k rpm area. and then out of nowhere my CEL came on. i took it to a local place and found out that it threw a fuel trim malfuntion (bank 1) code. im not exacty sure what that could mean.

any help would be greatly appriciated.

oh and its on a 97 gst 5 speed.