My 01 Sable with 52K has a problem similar to what jerrybarr posted. Coming off the freeway, the car will not decelerate normally. Switching to neutral shows the engine is revving at 1700 rpm while coasting. I also have the car lurch when I engage the transmission. The idle eventually goes down, but the lag time is excessive. I've cleaned the throttle body and replace the IAC motor, yet the problem remains. Any thoughts?