I know, I know, I've looked and my question hasn't actually been addressed from everything in the search.

My frickin exhaust is rattling, it's not the CAT shields, it's some vibration or rubbing and it's annoying and ghetto as hell.

My question concerning exhaust is:

Keeping a stock header, how should the header back be configured, concerning pipe diameter?

I'm seriously considering having everything from the header back done, and having stainless. Most everything only concerns the CAT diameter and back in the search.

I don't intend on changing the header. I don't intend on going larger than 2.25 diameter pipe, but I'm not sure what the front pipe diameter should be, and I'm not sure what the CAT in/out diameters should be. I also don't intend on anything other than stock N/A.

 

What kind of catalytic converter did it come with and how long have you had it?
What happens on older catalytic converters or a type of catalytic converter is that it contains a ceramic core. Over time, that core disintegrates and it becomes loose and starts rattling inside your cat. It may be very hard to tell unless you actually dismantle your exhaust system and look through the piping.

If you want something done proper, go custom, custom stainless steel catalytic converter with stainless core, ultra quiet resonator that contains fiberglass core, and pure stainless steel mufflers with stainless core.

I got all my stuff through vibrant performance, i know a dealer. best of luck!

 

I think it's actually rubbing the heat shield or car body somewhere. I was just under it yesterday but didn't notice anything.

The CAT is a direct replacement that I put on it about 2 years ago, only about 40 or 50K on it.