Will adding a Cat-back throw the CEL

[SittinOnDubsWGW]

Alright guys, quick question. My URAS cat-back should be here sometime in the near future and was wondering once I get it installed should it make the Check Engine Light come on?

I've had people tell me it will, and people tell me it wont.

I planned on running the stock cat with it, should this be fine? If not what should I do to make sure everything is going to be fine.

[thelinja]

Make sure there is a bung for the post-cat O2 sensor. That's the only thing that would throw a code.