i have a cusom cat-back on my car for several months, but have never noticed something until a friend asked me a few days ago. my car was started and she went to the trunk to get something. she asked, "is your exhaust supposed to be vibrating so rapidly?" i went out and looked at it and noticed that it was vibrating very rapidly and a lot also. if you put your feet on the tip, you can really feel the vibration. is this normal?

 

My dc exhaust does that too. Its more of a rapid shaking and not a vibration. I think it stops after it gets warm but I'll have to get back to you on that

 

lower rpm increase exhaust movement - like around 600-800rpm...

stock exhaust use spring-tesnion bolts at mid-pipe to muffler pipe connection to reduce the vibration, most aftermarket don't have spring tension bolts, so connection is more solid - therefore more vibration.

if all the connections are torqued to specs and theres no rattling, theres not much else to be wrong..

 

not too sure if it does that after the exhaust is warm, but i think it does. actually, it should be warmed up already since i was driving for a few hours at that time. there was stop and park, but from the time i ignited the car til the time my friend told me to look, it was a 25 mile drive already, plus idle time.

 

low rpm increases exhaust movement? really? didn't know that. prolly that's the reason since it was idling when i look at it. well, obviously, or how else would i be able to see it.

mine is a custom exhaust, so no connections. it's a straight 2.25" pipe from the cat to the exhaust inlet. there's no resonator either. so, can this be the prob?

does it vibrate so much as i am driving? cause i think it looks pretty odd if it does. anyone seen it vibrating while driving?