2004 g35 sedan with 115k miles
no dash lights got code for p1716 and u1000
transmission shift rought first or second time running through the gears then runs like butter! If i were to try and floor it from a light its gonna shift bad and sometimes slightly sloppy down shifts as well but for the most part runs and shifts great.... someone plz help befor i buy a new trans for it

 

Drop the trans pan and look for obviously damaged wiring to the input revolution sensor, it will be the two wires that disappear to the front of the tranny.

Might just be wiring that's broken or worn through, probably not a bad tranny since it's the issue goes away as it warms up, likely a damaged wire issue.