I have a 97 z71 4x4 and it has beed wierd since I got it,meaning that it acts up whileit is downshifting.I can be going thru a parking lot and it seems to idle about 1500 like a cruise control problem,you can put it in neutral and rpms go to normal...I have been reading that there are valves or soleniods in the trans that can cause downshifting problems if they get any trash in them...Does it sound like i,m in the ballpark here...Thanks