Unfortunately you are going to confuse 90% of the board with your description of what you did. You removed the rear mufflers, but left the resonators. You know the resonators are the "rear mufflers" right? Did you remove the resonators in the back and leave the mufflers(middle of the car)? If so, yes, you will have drone but can't really call it straight pipes(resonator delete). If you removed the mufflers(middle of the car) and left the resonator, then you shouldn't have too much drone.