stock exhaust piping size for 1998.5 A4 2.8Q V6 30V ??
i need to know what the size is so i can decide if i wanna go 2.5 or 2.75"..
im getting an exhaust soon and im going with 2.5 piping and cats, is that ok? ive heard going 2.75 is ok too...
any thoughts on this?

The piping is as follows for my 99.5 quattro A4

From down pipe to front of cat - 1.9"
After cat to y pipe - 2.0"
Y to front resonator - 2.4"
rear resonator to front muffler - 2.5"

This is stock piping.
Im sure using the standare 2x2" to the 2.5" with more free flowing mufflers will be fine.