94 sentra front end noise

#1

A couple of months ago I noticed a sound coming from the front end of my car. The sound is similar to a pusle of escaping air from a piston (not an engine piston) under compression. At first I only noticed it when going over the speed bumps in the parking garage at work. I now notice it when going over any significant bump. There also seems to be a small amount of deviation in my wheel tracking when changing lanes to the right. I was thinking that it is the control arm bushings. The dealership says the bushings and contral arm come as a single unit, and it will cost $500.00 to relace it. I am not all that confident in my diagnosis, and I don’t want to shell out this money unecesarily, and certainly not if it won’t solve my problem. HELP!

#2

I am sorry that should be a 2004 Sentra