Hi 727,I have been following this discussion since May and the one thing that stands out is with any pipe mod,3to3,3to2,3to1,involve a cat delete pipe.I have heard in person the cat delete pipe and the TOR's and it is quite loud.I have also heard the aftermarket Staintune 3to3 with the cat box and delivers a rich full sound.that is not too loud.I think my next move will be a cat delete pipe with stock pipes as I do not want a lot of decibles,just some.I think just pipes and cat mod should not affect MPG that much for a reasonable power gain.Now intake is something I'm still looking at.Nothing to worry about with the idle issue as I believe it is very isolated and involved the wrong factory tune.