[DUPLICATE ISSUE/THREAD]
I know this thread is old, but this issue still exists. I had a 2000 Cougar (v6) with this same issue... it started around 20k miles. I kept bringing it to the dealer, and they gave me the same line.. "Well, that's normal." and when I told them that it is a safety issue and that they don't understand the problem, they finally seemed interested. The several times I brought my Cougar there, I got it back unchanged. They said they couldn't duplicate the problem. So, I was driving to work one day, and the rpm hang was pretty bad, I dropped by the dealer and had the mechanic ride along. FINALLY they began to understand! They were able to test the car, while this problem was happening, and they found the problem. I believe it was some electrical problem, but since this was about 3-4 months ago, I can't clearly recall.
The reason I'm bringing this up: The lease expired on my 2000 Cougar and I just (1 week ago) picked up a 2000 Contour SVT... which has the same rpm hang!! As I'm sure you can imagine, this is very frustrating... and it only has 17.7k miles.
I'll try to contact that dealer to see if they have the record of what they did to fix this... and if others are interested, I can post the results.
[EDIT: The service center said it was the TPS... and it runs $192. I'm trying to find out if this is considered a 'maintenance item'...]