Sounds like a vacuum leak.
2006 MSRT8 in Brilliant Black, Options I,II,III, Sunroof and Sideairbags, Free Auto On Headlight Mod, Headlights on wth wipers, Highbeams on with Fog Lights, Hacked Nav, MOPAR Remote Start, BLACKEND I-Pass, Tailgate Plugs, 20% Tint Side Front Windows, Smoke LED Tailights, Airhammer CAI, Kooks LoKo Coated headers, Hi-Flow Cats, JBA 3" Cat Back, eibach sways. Fri Ported Intake, Fri Street Heads, Fri Littleboy Cam, P.I. 2800 Stall Converter, Custom Autometer 5 gauge over the visor pod, B.T. 65 Standard Hurst Shift conversion, TommyZ Hood S.N. 2. 180 degree T-Stat, BT Ported TB.