I have the headers w/ high flow cats, and magnaflows with resonator. The first 300 miles were great, nice deep sound, no problems at all. Then I got a CEL, and around this same time I noticed the exhaust note got really buzzy, there wasn't a single sign of it before. I thought it was an exhaust leak so I connect the pipes tighter, no fix. Then I thought it was a pipe rubbing against the underbody so I adjusted the entire thing, no fix. So now I'm wondering if anyone else with the same setup has this annoying buzzing sound that starts at right about 3k. And/or has anyone has fixed it? Are the mags just not suitable for all the added pressure?