I'm pretty close to installing the RK long arm kit in the front of my jk. It calls for relocation of o2 sensor and drivers side cat. I don't get smog tested. I don't know anything about exhaust and such.
1) What if I just took the cats out all together?
2) what if I only removed 1 cat?

Will I have check engine light on? Will it benefit me at all?

Pros/Cons?

Northridge 4x4

 

Following

 

Yes, you will throw codes and have the engine light on. If you remove them don't throw them away as they are worth quite a bit.

 

Dirtman is correct.
I have the downstream cats on mine hollowed out as they were clogged. It runs a bit rich smelling but other than that (and a bit throatier sounding) I haven't had any problems. If you do cut them out completely you can get a good bit out them at the scrap yard. Prices are down at the moment but you'll probably get about $150 or so.

 

On my F150 Lightning they made dummy 02 sensors that you could install and send fake signals to the computer.
Do they make anything like that for the 3.8 or 3.6 jeep engines?