If you have an automatic transaxle 4T45E do not do a tranny flush or so called fluid exchange service. You will be asking for trouble. A pan drop with new screen filter and ATF replenishment is sufficient if you are not experiencing any tranny problems. Plus you have to take into consideration the age and mileage of the vehicle.
Here's link to the latest debate we all had:
http://www.automotiveforums.com/vbul...smission+flush