Did you rotate the tires to determine if the pulling ceases or moves position in accordance with a tire location? If it does, maybe you have a bad tire.
The major cause of warped rotors is improper tightening of the lug nuts. First, you should hand-tighten the lug nuts with a torque wrench. Second, each lug nut must be tightened to the exact torque specification that appears in the owner's manual
