Trans sounds like it's slipping

I have a 2001 Millenia. When you slow down to probally 2 gear and start to acelerate again, it sounds like the transmission is having to down shift before it will acelerate (almost like a slip). I do have an airbag light that blinks code 37 and then eventually the airbag light goes off and then the check engine light comes on and then all lights are off for some time. I have checked the trans fluid and is fine, with no leaks.

Does anyone have any ideas? This is problem is very irritating.

Thanks