Car hiccups while idle and worse when driving

My wife has a 02 Saturn SL1 which is pushing 100k miles. The check engine light went on about a year ago but the car drove the same so didn’t get it checked out until last week. The auto shop said it was a intake manifold gasket was loose and allowing extra air in. After they looked at it the car ran rough with hiccups when driving and shook a little. After it was replaced it drove good for a week then this morning went wild. Turned it on and mainly hiccups and when driving the rpm’s don’t speed up real fast and will just stall and go back to idle then try to start up again. Going to take it to the shop and see what they say tomorrow but wondering if anyone knows what is going on. check engine light wasn’t on this morning but turned on this afternoon and now is on. Thanks,