Just got my new magnaflow 14851 race series mufflers installed, and was advised to keep the resonators on by the mechanic as the loud crackling from high rpms sounds pretty annoying. I left it on as per his advice, but I still get a crackling noise at high rpms or when revving my engine. Is this normal with/without the resonator for this car and muffler combo? Also, I have the 3.0 with stock pipes if that helps too. I can post a video if you think it would help, thanks.