stalling?
 

Still same issue as before on long trips my 06 AT will bog down and feels like its loseing power, I haft to down shift to get it to pick up speed the exaust gets all awful sounding.. I have not a clue. Mazda says its fine there test picks up nothing but the aftermarket mods. But there is a problem or it wouldn't be doing this. How do I get mazda to go more in depth with figuring out what's wrong with my baby??

Next time your car is acting up while you are driving call the dealership and see if the service manager is there and if so go to the dealership. Once you get there have the service manager test drive the car with you in it.

Do you have a cat converter on the car still?

Yes I still have my cat.