Borla Headers
 

So from what I have gathered from other threads, the UEL borla headers cause cel problems. But some of the dates are a couple years back so my question, has borla fixed this problem since these were initially released? Just got my FR-S a couple days ago so I am new here!:D

I don't really know that I'd classify removing your cat and throwing a cat CEL as a "problem". It's pretty much to be expected and has many simple resolutions.

It's really hit or miss. I had a borla with a O2 spacer on it and it threw codes constantly, always about the missing primary cat. I took the Spacer off and the CELs basically went away. They come back every now and then, but I just clear it and continue moving down the road.

Ahh okay thanks for some clarification! So it actually does not cause any "actual" problem. Just the sensor thinking its missing the primary cat.

Correct, you can either turn it off in your tune or space out the downstream O2 sensor to make it go away. You'll get the same with pretty much every aftermarket header.