Stock cat dead, should I get aftermarket instead of OEM??
 

Hey guys,

Running a 2002 A6 2.7T and my bank 1 cat on its way out. I wonder if anyone knows if I purchase a cheaper aftermarket catalytic converter (Bosal or something) for roughly $400 so that I can save myself about 600-700$$ will I have any problems? I have heard that non-OE catalytic converters simply don't do the job on this car, either by restriction or that it will still throw a P0431/2 code. Does anyone have input or a suggestion?

OR - should I perhaps start looking into performance downpipes/cats from another performance shop. Can anyone recommend a part??

Thanks bros!