Ok, so i just put on my header and downpipe from ca. I had a gmpp exhaust on there for awhile already. But i'm havin the most annoyin noise comin from my car. Thing sounds like a honda going up the street. Now i kno that my 2.5 in catless downpipe casues alot of raspyness and that so called honda noise. But this is different, its only when im drivin really slowly through the rpms: it buzzzess. lol But I can't figure out wat it is ive never heard it come out of these cars and all the videos ive ever looked for never had it as well. They were just raspy and more annoyin lol.

My question or solution is put a high flow cat on the downpipe?? Maybe add a resonator somewhere either on the downpipe itself or another one somewhere in my cat-back?? I've completely checked the system for leaks ect. All gaskets are new and bolts are completly tight. Just for some reason can't figure this out?? Any help?? Thank you