popping noise?

yesterday i was driving my friends 97 LS and when i was idling or sitting at the light the car felt like it was dying. when i take off i still feel the shake until i get to about 30mph. i think the exhaust piping had a hole in it or something im not sure. i think its this because when id stand behind the car the exhaust would putt not flowing all the way through. cutting in and out.. it was weird any help would be great