[jimfin]

There is something that I noticed and are wondering if anyone else with the V8 Automatic hears the same thing. When I'm driving in the streets and i hit the gas and get the car up to 2000 rpm's it sounds normal. If I have to slow down and the rpm's drop down to 1200-1400 rpm's there is a sound that comes from the engine almost as though its down shifting, but its very pronounced. I don't lose any power, but it doesn't sound right to me. I had my exhaust upgraded (GM Performance) and an air box installed and now the noise sounds more "raspy" for lack of a better word. My machanic noticed this, but had no explanation. He really doesn't know enough about the car to tell me if this is normal. Is it possible the L99 engine steps down cyclinders (goes from 8 to 6) at lower speeds and thats what I hear. Any help will be appreciated. Thanks