[roblese90]

Are the bmw performance exhaust midpipes the same as stock just without the resonator? Or are the midpipes a different diameter?

[SonicBlueStage2]

That's correct. The resonator is replaced with a Y Pipe, but that's not where the biggest difference in sound comes from. There are significant differences in the internals of the muffler. Some people have modified their stock back-box to try and replicate the PE but I would just get replace it with the AA gen2 muffler.

Stock exhaust:



Performance Exhaust:



AA gen2 muffler:

[roblese90]

Originally Posted by SonicBlueStage2

That's correct. The resonator is replaced with a Y Pipe, but that's not where the biggest difference in sound comes from. There are significant differences in the internals of the muffler. Some people have modified their stock back-box to try and replicate the PE but I would just get replace it with the AA gen2 muffler.

Stock exhaust:



Performance Exhaust:



AA gen2 muffler:

I had installed the aa muffler on my previous e90. Although it did sound great, it just didn’t quite have that sound that the bmw pe has

[sq86]

Correct, it removes the resonator but not the secondary cats. I have removed the secondary cats by getting a Supersprint section 1 piece (connects to the header) so it mates to the BMW PE exhaust. I think it sounds great and it doesn’t throw and CEL.