128i replacement catalytic converters

[Zellgrav84]

Hello,

I am pretty new to the BMW world, and currently own a 2009 128i. I have had to car around 10 months and love driving it, however there is a problem. The dreaded 0420 code, the cats are going bad. As I am sure you all know the OEM cats for the 128i are insanely expensive. I have two fairly simple questions. 1: Magnaflow has replacement Cats for the 128i at a more reasonable cost, are they worth getting? 2: Is replacing them something I can do myself ( I have a decent amount of know how working on cars)?

Thanks much!