My car's a '97 SE, 147k. After I get off of the interstate for about 45 miles or so and slow down at the end of the exit ramp my car acts like its going to stall out! What the heck? It hasn't stalled out, but the idle drops waaaayyy down, like 300 rpm or so. This is not normal behavior for the car, and after a little more driving around in town it won't do this anymore. Any ideas? I'm fresh out.