Why do I still have shifting problems after having a new sensor put in?

There are 2 sensors located on the fron of the tranny, an input and output sensors. They are located directly under the battery and about 15 dollars. It is a pain to get to but also allows you to see the transmission module bolted to the left of the sensors. Did the car throw a code, if so it needs to be scanned to get the number and the parts shop will give you the reason. The module is about 80ish and is held on with one bolt. If it has fluid all on it, then it is leaking internally and done for. BTW then last did you have the tranny service done? Ck the owners manual, I think about every 25k or 50. I do mine ever 2 yrs roughly 25-30K.

transmission filter clogged ,