I'm guessing there's an exhaust leak somewhere. It's more audible inside the car than outside, if that makes sense. In fact, it's almost inaudible if you're not in the car. Also, there is a small popping sound in the right side (passenger) exhaust. I'ts faint but is noticable when I crank her up. There doesn't seem to be a certain rhythm to it. Have checked header bolts and intake bolts - running out of ideas. Could it be a gasket or a leak in the pipes somewhere? Seem to remember something from another post about combustion inside the mufflers. Thanks for any replies.