I recently cut off the stock mufflers and in its place I got 3 inch pipes welded. The sound is amazing, nice and deep. But, at around 1500-2000rpm I get the infamous drone. I have the stock pre-muffler and resonators in place. Would the larger diameter piping cause this drone, because Ive read that the stock resonators and pre-muffler should be able to cancel that out. Oh, and do you think I've gained any hp by doing that, or even increased MPG? lol

 

, oh and some videos

yeah, itll drone.