Recently Purchased 91 Sentra

I recently purchased a 91 sentra. I am not sure of the engine, I know that it is a 4 cylinder as I believe they all are for that year. I have a few issues and need a little guidance. Upon accelaration it is very sluggish. When I push the gas all the way runs fine. Decceleration it gets sluggish again. I plan on changing the plugs. It's rather cold here so I am going to wait until it warms up. Is there anything else I should change as I am doing the plugs and wires.
The exhaust sounds pretty bad as well. I believe there is a hole in the pipe right before the muffler. Any quick fixes? Any other info would be great.

Thank you

sounds like it hasn't been used in awhile and a tune up should perk her nipples up a bit. what's the mileage

Check the distributor. And make sure you use NGK spark plugs.

NOT BOSCH!!!

Also, check out this thread:
http://www.automotiveforums.com/vbulletin/showthread.php?t=480607

It has 184,000 roughfly. I have a feeling that when I tune it up it will run great. As is it gets 26.4 miles to the gallon. It's better that my blazer at 18-20. Well see. I'll keep posted. Sorry to all about not know my info, I just saw the noob posting you have. Like I said I haven't had a lot of time to look at it.