Hi , I have a 1999 Sonata v6 with Automatic Transmission , I go it from some guy here in Mexicali Baja California, yeah in mexico, so it had 109k Miles on the od. , now it has 125K on it, so some times the transmission feels strange, like it sticks when wanting to shift down like 3-2 or 2-1 , so I was thinking , can it be an old ATF? The car runs fine, I use the car when traveling on Highway , so I don’t really know if the transmission has had a services some time on its life or it haven’t had a service at all , so I know I need ATF SPIII but should I change it or not? Its like it down shifts slowly , when coming to a stop it delays shifting down, and when wanting to accelerate it has a delay when downshifting , but the transmission works fine I guess but is this normal or it has something to do with the ATF? Should I change the fluid an filter?