I have a 2013 Carmy. When I turn on the AC, the MAX also comes on. I don't have temp the knob in the MAX position. So when I turn on my AC I manually turn OFF the MAX. Is this normal?

Without a picture of your AC/Heater/Vent System...it is hard to say if your system is operating "Normal". Suggest you consult the Owner's Manual for the proper operation of indicated system.

Bobby...any updates on the issue with this vehicle?

Yes - In doing some additional research on this, my "Understanding" is that this is how this AC system IS designed to operate. Basically, MAX (Recirculated Air) will be automatically enabled when the AC is turned on and the air outlet is directed through either the dash vents or the dash vents AND floor. It supposedly can reduce fuel consumption?? This leads me to another question: When the AC system is in the MAX Mode (Recirculated Air) is the air still going through the cabin filter? When MAX is selected I hear an increase in fan speed and wonder if it is because the filter might be bypassed when inside air is the source. I suffer from severe allergies and feel the cabin filter is a help to me.

I believe ALL air being recirculated, and the air coming in when the system is out of max...and...outside air is coming into the vehicle is indeed filtered. As you probably know the Cabin Filter is usually located behind the glove box. If one would access that filter...and remove it, one could observe the operate the system in various position and feel/hear air flow. Changing the filter often should help/relieve your systems. Try it.