well i'm sure you can see what it does. if you take it out, you put more stress on the exhaust studs and the bolts between the downpipe and the cat. i put on my dcs headers and i didn't attach mine and it seems alright. so it's up to you, really. these aftermarket headers are MUCH lighter than the stock pieces so the stresses on the bolts and studs won't be as much as if it was the stock pieces.