1997 Pontiac Grand Am Car Stalls when stops

My car just recently started to stall when, I either make right turns or come to a complete stop. I also notice when I am driving the car stutters from time to time especially when at speeds greater than 50. The car starts to jerk like its about to cut off or like the transmission is about to give out. I sent it to the shop to see if the problem could be found at first I thought it was the ignition module because for a while after I got the car back it it was not doing it. I just want to find out the issue because i'am really sick of spending money on a recurring problem