Since it's cold here, my 08 Grand Prix is a little weird ...

Sometimes, my idle is at 750 rpm ... and sometimes, it's at 650. No variation, just steady at 650 ( scangauge 2 ) . I feel a little little shaking when is a 650 ... Like little missfire . I cleaned my throttle body and it was very dirty but no change for my idle.

Yesterday, my car had a little hesitation at a stop but nothing more than that.

What to do now ? MAF ? Crank Sensor ? IAC ?

Thanks !