I need help

Hi I have a '00 saturn sc v4 with 122,000 miles on. Within the past week whenever I ease up to stop it jolts when the speed drops to 15mph. Almost like a jump. Other then that the car is ok. It make like a roughin idiling noise when my rpm's hit like 2 but then it goes away. This happened last winter too and the place I took it said I needed a new map sensor and a fuel treatment I do fuel treatments every couple of fills. But its not kicking it. What is your opinon?