Do I need tuning?
 

Since I installed the Pacesetter longtubes and 3" y-pipe with dual cats, the exhaust smells rich at idle speeds once the engine is warmed up. On yesterday's trip up to TTP I could smell it at the toll booths and when I got home. I checked my gas mileage by filling up when I got home and I got 23 mpg yesterday which was mostly I95, Turnpike and Parkway. I have an A4 with 3.23's and the 315 tires but I was expecting a little better mpg with the headers. I used to get 24-28 mpg with my supercharged 93 with the A4. My block learns were running around 3-5 above baseline so that would indicate the computer was actually seeing it being slightly lean(makes sense with the better flowing exhaust) so it was adding some fuel. It's mainly the smell of the exhaust at idle that makes me think it's running a little rich.

probably, when BLMs are 3-5 you can use a LITTLE bit of tuning, its nothing to be concerned about tho IMO because 3-5 isnt bad