1999 Dodge Truck Shifting abnormal

The vehicle is shifting abnormal. I first noticed this when driving the vehicle and it stalled at a red light it acted as it was still in 4th gear when it should have been in 1st. I restarted the vehicle with no problem and it didn't do it again. However, the engine check light came on, and ever since this, the truck when shifting out of a gear will jerk a little bit the RPMs with increase and decrease without me varying the gas pedal. It almost acts as it is can't decide if it should shift or not. I really notice this when I slow down to make a turn and start up a hill right after the turn. I also notice it not being right when I am stopped, and I do a quick acceleration (not even the type to where I'd expect to spin the tires) it will start off normal then when it is about 3/4 through a gear it will seem to get more power out of no where and then do a shift. When I am moving and give it a lot of gas it will down shift normally but stay in the gear longer than it used to almost red lining. I took this vehicle to the shop and they used the thing to tell why the check engine light is on. They said that it was a fault with the speed sensor in the transfer case. I had them replace the sensor and reset the light I pulled out of the shop and the light kicked on with in 900 yards and the shifting is the same as described above.