I just got a full tune-up and put on a cold intake. I also replace front and back brakes and rotors. The hesitation is gone, which was caused by bad plugs, but now when I pull off with from first I feel a grinding noise, almost like a roar. It goes away once I get into 2nd or higher, but I'm not sure if thats because the speed dilutes or not. My guess is it could be the brakes but I'm not sure. What do you think?