Is it me or are there flat spots during acceleration when I press down on the gas pedal? I have a new "05" av Z71, 5.3L AV It only has 5K miles on it. If I am cruising down the road, and give it a little gas, it seems like the engine says, "WHO ME?" I have to give it a little more pedal before it responds. I in stalled a Magnaflow dual exit exhaust, but did not seem to help. Has anyone else had this problem? Thanks, Pureh2o.