Looking for an 02 Simulator

I live in a state that doesn't have mandatory exhaust testing, so i punched the 1st stage of my cat conv through with no probs, and i want to do the same with my main cat. Where can I get an O2 simulator for a reasonable cost?? I have K&N intake, hi flo muffler, 1 cat punched through...any thoughts on cheap hourspower outside of supercharger and stuff like that? :rofl:

www.urdusa.com cheap hp= header, freeflow cat, muffler, and intake mod. Thats about it.