Intermittent rough idling

I have a 1999 Toyota 4runner SR5 3.4L v6 with about 187,000 miles on it. I noticed it has rough idle and lately has been getting worse. The idle happens when I am stopped at red light or when its just sitting running. When I am stopped at red light it idles really rough and acts like it wants to die. I have to put in neutral to give the engine gas and then it stops the rough idling. For instance I stopped at the atm machine it idle pretty rough then the engine sputtered like it was gonna die and I gave it a little gas. I took it to my local repair shop today & ironically it ran perfect for them so they could not duplicate the problem. The only thing their diagnostic found was my 02 sensor was going bad. They told me to bring back when it does it again. Any ideas what might be causing this?