RPM surging when in park and neutral

[david23]

hi everyone. I have a problem with my s80, for the past 3 months i've been having a problem with my s80 rpm surging from 0 to 1 when in parked and in neutral. At time it seems like if the car is breathing, and it usually vibrate the entire car. Can anyone help me to figure out what the problem is or has anyone have that happened to you? I took it into dobbs a bunch of times, change everything from o2's all 4 x2, mass air flow sensor.

Thank You
David