Will be cruising at highway speeds going up a slight hill and car will start to shutter like it is about to drop inot a lower gear to concour the hill. It will only stop shuttering if i stomp on the gas to make it down shift into a lower gear or if i manually put it into third gear. Could this be the torque converter clutch sensor going bad or something else?

Also the car is a 97 gt 3.8 liter with 77,000 miles.

Yes, this certainly sounds like the TCC solenoid sticking. You will probably need to get it replaced however take the car to a tranny shop and have them diagnose it before jumping to conclusions. They should be able to tell within a few minutes what the problem is. This is a $500 repair and it is not a DIY job.