1992 Saturn Sedan chuging

Shakes or Wobbles problem
1992 Saturn Sedan 4 cyl Two Wheel Drive Automatic unknow miles

my 92 saturn at a steady speed chugs and shakes like it either wants to take off on its own or die. I had to put a bottle of gas dry into it cause I live in florida and we got alot of rain also as it sat for 3 months also added a bottle of fuel injector cleaner to it. I took it to a shop who told me that the computer needs to be replaced but I do not belive that is the case and want a second opinion