What's up with my truck? 2008 1500, 4x4, 5.3l, ly5, small cam 218/224 .552 @ 113.0, heads milled .030, ported and polished heads int & exh. After getting my tune pretty straightened out where i happy with it the only thing missing was that sound of flows on a SBC so i took the exhaust off and deleted the cats, built a new system with 2 1/2" duals and 40 series flows, deleted rear o2's, no CEL, engine pulls good still but man it sounds like sh$%. Popping in the exhaust at idle (14.3-15.3afr) and at a certain rpm (1500-2000ish) it sounds like the baffles are broken loose in the mufflers with a really tinny sound to it. Wide open about the same with 13.0afr. Truck has manifolds not headers. Is there something that is in the tune that could cause this or is it how the LS sounds? Sure isn't an old 350.