So my GS has some power issues sometimes. Say I'm going slow or taking a turn, and accelerating again once out of the turn. It gets stuck in 4th gear for some reason and doesn't down shift for more power. I have to step on the gas pedal half way or so to actually get it to downshift. What's going on? It has good power when starting from a stop light etc.

 

Does the car get stuck in any other gear? Any other odd transmission stuff going on? Has the fluid been flushed and up to date with service?

 

No. Just when going slow 20-30mph and stepping on it to gain speed, it just doesn't downshift... stays in 4th or whatever.

 

Have you checked your fluid?