I have a 03' mustang v6 with many mods and I unhooked overdrive to install new shift knob and rewired overdrive wire to toggle switch(still works). But noticed when im deaccelerating from anywhere from 55 + my car does a kinda hop/jolts back and forth two-three times. Took it to shop&said the only thing they could figure is that it was the toggle switch sending disruptive signal to pcm box.So I waited a little bit and got switch fixed in momentary touch(like stock) and its still continues to do the same.Any ideas?
tranny? or something else?
Knocking in tranny? 
Hope you get your answer..
