I'm currently looking to buying a Milltek exhaust for my Xkr and I do not want any backfiring or crackle on overrun or anytime. The YouTube video of the blue cabrio sounds perfect but then another video has a black Xkr which when revved hard backfires. Is that because it has hi flow cats or strt pipes . If I keep my stock resonators will the crackle not be present . Thanks in advance

Regards Jordan

PS I have done searches and read all the postings re exhausts but could not find a conclusive answer. Ghostrider I am hoping might know but i realize he put the milltek exhaust and hi-flo cats at the same time.

 

It could be that is it caused by the factory 5500 rpm limitation when the engine is not under load.