Vibrating from floor and weird sound when I start my 93 jeep cherokee?

When I start my 93 Jeep Cherokee the floor seems like vibrate and or shake a little bit and make an odd noise i can't describe. Can someone tell me what this is?|||I know what it is. It is the bracket from your exhaust to the cross member below it. It broke and now the exhaust rests lightly on the crossmember and it will go away with moving down the road but at stops and at low speeds you can hear and feel it. You can buy an after market exhaust hanger and fix it that way if you dont have a welder to reattach the exh. bracket. The only other thing id look into is your u joints. See if they have play in them and if so there you go. Thats about all that will make a vibration in that model year truck.|||could be your catalytic converter cover comeing off