BMW M3 Forum (E90 E92) - View Single Post - Challenge Street mid + M performance catback. Anyone?

kitw · 02-03-2013, 12:50 AM

I've found that resonators do cut down on the rasp somewhat, but not completely. I really don't think removing the secondary cats is worth it, I think it's always better to remove the primaries with a $400 test pipe.

02-03-2013, 12:50 AM	#8
kitw Colonel Drives: 2013 AW E92 M3 ZCP M-DCT Join Date: Jun 2007 Location: Bay Area, CA Posts: 2,133 iTrader: (13)	I've found that resonators do cut down on the rasp somewhat, but not completely. I really don't think removing the secondary cats is worth it, I think it's always better to remove the primaries with a $400 test pipe.