Catless header... o2 bungs before/after front pipe cat?
 

-Running Autocross in STX class , so I need to keep the rear cat.
-Front cat can be removed, looking at catless EL options.
- DO NOT want to deal with CEL issues, tune is a ways off.

Given these conditions, why not run a catless header with the o2 sensors relocated to before and after the front pipe cat. I have done some looking but haven't found a front/overpipe combo that has these. The Nameless combo pipe looks nice, at this point is my only option to have the bungs welded in? I'm running on the assumption that this will work fine, correct me if I'm wrong here. I see o2 wire extensions, anyone have experience with these?

Any input is appreciated.

You better off spacing out the rear O2 sensor. With just the secondary cat you'll most likely still get a 420. Use one of these: http://ft86speedfactory.com/o2-spacer-for-cel-1090.html
Or a spark plug non-fouler if you're the DIY type.

Well I've done a bit of research and some people still end up with the CEL even with the extension. After thinking about this a little more, maybe I will replace the secondary O2 with my own wideband sensor and then relocate just the rear sensor to after the secondary cat.
@pche Why would you say I'll still end up with a cel with just the secondary cat?

Because by just looking at it the secondary cat looks significantly smaller, therefore I assume it doesn't perform as well as the first one. I have the catted
header set up and it still sets the 420. I spaced out the rear O2 sensor with a spark plug non fouler and haven't had the code come back.

Fair enough! thanks for the info.

Also also! Anyone have input on this, as in does it apply to our cars?

http://forums.nasioc.com/forums/show....php?t=2234058