Yes, it comes with the DB Killer insert. I like the sound better with it in actually BUT, I like the power/performance more with it out so the squid in me won out so I took it back out.I've got my eye on this slip-on as well, but I'm a little skittish about cutting up my stock system. Thanks for the pix!
One question: does this M4 come with any kind of "dB-killer" insert? I don't want mine to get obnoxiously loud, but I'd love to save the weight.
As poogamer said is on the inside of the pipe hidden which I prefer visually. Heres a shot of that https://www.dropbox.com/s/t4h7l9163ieyucc/2014-03-21 13.48.14.jpgHey cogent Where does the O2 sensor go?