Ok so as I did more and more into my new 2011 Cooper S I'm learning more about it. So previous owner installed the JCW brake duct work , complete kit not just the grill ports, my exhaust has the down pipe cat and the flex joint then is straight thru to the rear muffler with dual center outlets. Still haven't dug into it to see if there is an after market diverter valve but it does have the Forge type boost tap under the IAT sensor in the intake manifold. I was looking into the noise maker delete and it appears my car never had one. There is no joke thru the firewall where one would have gone but I do have to remove the IC muffler soon. My car has a build date of January 2011.

 

There is a factory noise maker delete that came on the JCW’s, you can buy the part separately. Run your vin, might be a jcw.

 

N18 engines didn’t have the noise maker pipe.

LCI R56 Cooper S front bumper had brake ducts as stock.

If there is no cat or resonator in the exhaust, it is an aftermarket system.

 

Good to know thanks njaremka. I think my exhaust is stock with a resonator delete. It appears to have a welded in section about midway between the flex joint and the rear muffler.