Mickf29

Anyone else ever wipe down the tailpipes of their RS4 and notice one is significantly sootier (is that a word?) than the other? My passenger side was much blacker inside and on the edges than driver side.

I could only guess as to what causes this....probably not a good enough guess to post here, because I really have no clue.

TwentyValveB5+S4

one bank running richer than the other? Maybe a faulty O2 sensor on one bank?

ELEVENS

Don't think so - the RS4 doesn't have a true dual exhaust system (banks merge @ the resonator)

S4Pazz

until I open the throttle (>50% or so). I don't know why and the car drives great. Thought maybe it had to do with the valves opening. May be that there is one predominant exhaust pipe. I very admittedly don't know much about the exhaust set up, but it is stock FWIW.

Mickf29

Who knows, but the car is running great so not too worried about it yet. Just seemed strange.

TwentyValveB5+S4

I could have sworn I've seen an under-car shot that was true dual all the way back... maybe it was a custom job?

ELEVENS

<center><img src="http://www.karlabs.com/WGR/RS4/h/h9.JPG"></center><p>
I'm guessing a true dual exhaust on the RS4 would sound like **** with no performance improvement. Even an X-pipe sounds horrible, this is why people use an "H" pipe on the RS4.

Picture is the stock 2007 RS4 resonator next to the ECS Tuning "H" pipe.

TwentyValveB5+S4

beats me

JPVsRS4

I took a look today, passenger side has more carbon than the drivers side.