I have been trying to do some more research on this for my car's exhaust and trying to work out what the real difference is between E90 build before 06/06 exhaust.
When I had a look under my car it looks pretty much identical to the US Spec ED91 on the DIY guide: See pic below:
The only difference being is I cant seem to see the 2 cat converters at the front of the exhaust on my car. Perhaps need to get right under my car.
What I wanted to ask is in the pic is that a resonator/muffler before the final muffler or is it a Cat converter?
If it isn't a CAT converter and my car has CAT converters at the front Why couldn't I just buy the US Spec BMW PE exhaust with Mid pipe and it would solve my problems?
Any thoughts would be great. Infact any one with E90 build before 06/06 who can clarify would be greatly appreciated.