You probably need a new accelerator pedal assembly. It has the throttle control rheostat on it that measures pedal position for the engine computer to adjust the throttle body plate, etc. They wear out or can get broken over time.
2006 Inferno Red SRT8 with groups I, II, Sunroof, K&N drop-in filter, Auto-dim mirror, Jet-180 T-stat, Predator, 300 SRT struts/springs, Chally SRT wheels.
Born 6-21-06, Home 4-26-10. 1/4 mile - 12.989 @ 108.78 in street trim. Traded 10-19-2012.
2006 Inferno Red R/T with R&T Born 8-12-05, Home 8-25-05, Sold 8-9-10.