Anyone had idle issues like this??

YOUCANTZME

Hey guys, new to the forum here. Just bought a 2012 Nismo, pretty much sight unseen (saw many pics but didn't drive it) and it seems to have some issues with the idle. I tried googling it but didn't seem to find the same problem I'm having. I plan on taking it to the dealership (still under factory warranty) but I wanted to see if maybe anyone else has run into this type of problem. Would love for it to be a simple fix (usually not my luck though) and save me a trip to the dealer.

Anyways, here's what's happening: every time I shift gears, the idle seems to hang at whatever RPM it's at. It doesn't drop like it's supposed to making it surge at darn near every shift. If I come to a stop and hold the clutch in, it will rev at 600-800 but it will spike a few times to 2000-5000 RPM's like I'm giving it gas, hang there for a second, then drop back down. Very annoying because every time I stop next to any car, they think I am trying to race em. The car is bone stock at the moment (from what I can tell, no intake, stock exhaust..etc..)Anyways, figured I'd throw this out there to see if anyone had any ideas. If not, it's cool. I'll take it to the dealership and post whatever they find, in case anyone else runs into this. Thanks in advance.