SS exhaust pipe flanges(SS or regular steel?)

[Konstantin Bogach]

Hi lister.
I need to evaluate the quality of SS exhaust on a car I am lookint at to
buy.  It has 3-inch tubo back.  It has flanges made of regular steel.
Is it normal thing?  Flanges are rusted pretty well on 1 year old
exhaust.  It also has 2.5'' secton right before the muffler. They put it
there to make it quieter.  Did it kill all purpose of 3'' setup?  It
also made of reqular steel and started to rust.

Konstantin.