1998 Other Saturn Models RPM spike then Stall

I drive a 2000 saturn sl2, my car spikes while downshifting but doesn't stall out. Every mechanic says its normal but yet they can't give me a reason why it is doing so. I was looking at other forums and the best solution that I am going to try is to have the computer reprogrammed to correctly regualte the automatic transmission. If you have any other ideas let me know. :]

ps. Your rattling may be the variable tumble control system plates ar closed in the intake manifold because its happening at those rpms. Try replacing the vtcs valve.

Thanks, I think I found out what was wrong with it I hope, currently my local car doctor is looking at it. The timing chain decided to go and put a hole in the valve cover. So hopefuly after all is said and done it works a hell of a lot better