The other day the S light came on and the tac started acting radically. the car is running but I have to keep a key in the shifter release slot and shift manually any ideas? In advance thanks

 

welcome to the forum. the transmission control module (TCM) may be going out. You might try to see if you can get the code to get closer to the cause of the problem.
try this site for more info
http://autorepair.about.com/library/a/1i/bl809i.htm

 

I'm no expert but when my S light went on all I needed was my sensor replaced.

I also had a few vacuum leaks that caused my RPM to go off a bit. All it was was a few busted hoses. Replaced and fixed it. Does the car sound like it's going then goes softly then goes then goes softly? If so I think it's a vacuum link and entirely different from the S light.

 

I took the advice to have the Transmission computer checked out. It had a burned out resistor. I found a place in east TN that repaired it for $60 that is if you purchase it on Ebay otherwise it would cost $160. Works fine now.
Thanks all