Pop in steering

I have a 2002 Grand Prix GT with 150,000 miles on the car. Sometimes the steering has a pop when I turn the car to one way or another. It is much more pronounced when the car has been parked for a little bit and the wheel has to be turned to be backed out of the yard. I'm figuring it is probably a bushing in the steering somewhere since it seems to stick while parked but have no idea other than that. Is there some way to determine exactly what is causing the problem. There is no other problem other than the occasional popping noise but I figure it is a sign of a problem in the making and would rather take care of it before it gets worse.

Mine did that too, was very rusty strut mounts/bearings

other possible cause would be ball joints