Valmor

I will have RS4 clutch upgrade next week and want to do something about my exhaust (once it is removed anyway).
Right now I am running custom-made "test" pipes (no cats) with Sebring cat-back. I don't like the sound too much especially when it rattles under load.
As an option I have on hand a full RS4 system (turbo-back) at practically no cost. So what is your advice?

1. If I put RS4 DPs shall I gut it? Do I need any special adjustment to fit it to my Sebring exhaust, which is the same diameter as S4 OEM system?
2. Will it make any benefit if I put the whole RS4 system with bigger diameter? Or shall I keep my current Sebring cat-back?
3. RS4 DPs have ceramic cats, which are very sensitive for rich mixture, as I've heard. While I am running an "aggressive" MTM chip with 1,4 bar boost. I am afraid that this chip "suppresses" O2 sensors to some extend allowing the mixture to go rich to avoid overheating. So wouldn't it harm ceramic cells specially if I gut precats?

TIA
Valery
Moscow, Russia

Qiish

Thought they were made of metal mesh (see link)...

Anyway, I may be going the same route and connect used RS4 downpipes to my Milltek dual catback. Think they will connect without problems.<ul><li><a href="https://forums.audiworld.com/s4/msgs/1009036.phtml">https://forums.audiworld.com/s4/msgs/1009036.phtml</a</li></ul>

SmokinS4™

The inner diam is 10% larger over stock at 2.3-2.4inch

Qiish

Have you (or someone else) tried to remove the metal mesh from these precats, and how do they compare against aftermarket downpipes?

Thanks for sharing this information...

SmokinS4™

but basically they look the same as S4 DPs, except they are 10% larger.<ul><li><a href="http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&amp;category=33630&amp;item =2421928344">http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&amp;category=33630&amp;item =2421928344</a</li></ul>

Qiish

The placement of the last O2 sensors gives the answer to my second question...