1997 Pontiac Grand Prix Replaced Lower Intake That Leaking Antifreeze Put

i replaced the lower intake that was leaking antifreeze and put everything back just as it came came off and i replaced the plugs when i i fired it back up it sounded good but when drove it i kept dieing but ran good when it ran so i cleanded the coil pack up good it stoped dieing but fell on its face when i dove it i changed out the coil pack stiil ran the same. ran fuel pressure check it was good . it set a code of multiple miss fires i checked every looked good but still fell on its face. then it also ran a map sensor code so i am extremely lost! any help would be great.