2005 2500 cc ram. stock... has a little hicup at idle other than that runs good. now when u step on the go pedal and release it takes at least 30 seconds for truck to return to idle. scanner says poor fca performance. replaced fca, helped a little, but still does shows fca code. and truck still is slow to return to idle. maybe 10 secs now. Could this be a injector problem? makes truck hard to drive anyone have any ideas on what to do next, or check?