the ck engine light comes on and goes off. It starts sometimes and not the next.

What is your question?

I had someone plow into my front end while it was parked. It was fixed and seemed to be running fine. All of a sudden went to start the car one day and it just would not connect. left it over night, next morning started fine. and then the check engine light was on. over the next few days the car would start sometimes and not other times. the ck engine light would come on and go off. I took it to O'Reily auto part to check why the ck engine light is on and he said the computer said it was the transmission speed sensor. Does that sound right and how costly is that to fix?