I have a 2006 3500 dually and with the truck running and in nuetral if you rev the motor up then let off the pedal the motor stays reved up for a couple of seconds then slowly idle's back down, could this be the FCA (fuel control accuator) sensor? Also truck doesn't have much power driving down the road. I think the same issue is causing both these problems, and I don't think its a injector problem because just had #4-6 replaced when dodge told me that was the problem and it still does it.

 

any codes? fca problems can throw an 0251 code.

 

It hasn't put out any codes.

 

maybe do a search on reseting the aps (accelerator position sensor i think). i remember other threads from others having similar problems...

 

Where is the APS located at?

 

I failed to mention one other thing, and that is when you unplug the turbo sensor located on the head and rev the engine up it idles back down smoothly, so I replaced that sensor but when pluged back in it still does the same thing.