I was going about 80 mph and had to get on the brakes pretty hard, and the car felt like i was loosing control, felt like it was gonna fish tail, it felt like was starting to point to one direction then overcorrected feeling for a few seconds. Tires never locked up or squeeled, i have 5 days old 235/35/19 proxes 4 on. So do you think this is a piston malfuction, or warped rotors? To much power on the stock brakes?

 

On real world roads, just ramming on the brakes at high speed will result in the car feeling a little bit squirrely. This can be compounded by an improper alignment or uneven pavement.

You can learn to apply the brakes very quickly but smoothly with a little practice. Another good car control lesson you learn by driving in HPDEs.