I replace my stock rotors with power slot slotted rotors and changed the pads to aem pads. After that I notice that the brake pedal still pulsates and the steering wheel wobbles back and forth when I brake from about 40mph +. What do you think is the problem and how do I fix it?

 

I am not 100% positive, but it could be an axle... this is what a mechanic told me a while back, haven't experimented yet because I think one of my rotors are warped