Thank you for all the information yuo provided. Unless BMWs have something that separates them from all other cars, I have a hard time understanding that an aftermarket cat would fail prematurely. All exhaust systems post-carburetor days are basically the same setup. If the o2 sensors are working properly, and the cat works, it should not fail anytime soon. The only thing running through it is air and fuel no matter what car you drive. I know as far as Hondas and Toyotas go, you can put virtually any cat in there so long as it fits, and it will do the job. If there is something I am overlooking though, please let me know. But based on my experience, all exhausts are pretty much the same. |