View Single Post
      06-16-2011, 07:30 PM   #2
kitw
Colonel
 
kitw's Avatar
 
Drives: 2015 MW M3/2011 E90 M3
Join Date: Jun 2007
Location: Bay Area, CA

Posts: 2,338
iTrader: (14)

The challenge street will pass the tail pipe and OBD-2 tests, but won't pass visual since it eliminates the secondary cats. (most places won't catch this)

None of them will produce power without removing the primary cats, though. You might as well do a Challenge Sport, Turner test pipes or Innotech if you don't mind some rasp. The Gintani/MXP/Fabspeed that put HFCs in the same position as the stock cats won't make power like the the ones that move the cats downstream.
__________________
IMG_3969-Edit by kitw, on Flickr
kitw is offline  
0
Reply With Quote