Not sure if anybody here has had any experience with O2 Simulators before but figured I'd ask anyway. As I understand it, the front O2 sensor does all the work calculating fuel trims and such. Supposedly, the rear only relays information on the condition of the catalytic converter to make sure it's working correctly. I've got a rattle in the exhaust of the converter of the Jimmy and I'd like to get it fixed. Even with my discount at Advance, a new converter is still $280. Frankly, I'm having trouble justifying spending that kind of dough on it if I can find something else (i.e.: a straight pipe) to replace it with and yield better fuel economy/power. Not that a Jimmy is built for power to begin with, but it does seem to be lacking some oomph when I'm towing the 4-wheeler. I've got a couple options as I see it.

First, we have spark plug anti-foulers at work that are pretty cheap. Essentially the same idea that these folks have only a lot cheaper...
http://www.voodooboost.com/performance_acc...s/O2_Simulator/
With their idea, you still keep the rear O2 sensor hooked up, it is just spaced out so that not as many gasses reach the sensor. Which I suppose is ok, but it's not an exact science either as (well the way I understand it) it only spaces it away from the exhaust and does not guarantee that it gets the proper resistance across the sensor that the ECU requires to keep a CEL from popping on.

Next is an actual plug-in replacement. This replaces the rear sensor all together and you close up the rear O2 sensor hole.
http://www.afterthoughtsauto.com/o2sim.html
I don't think there is much problem with this other than the possibility of buying it and it not working or being a scam. I do know that there are people out there that have had luck with this style, just not sure where they're buying from. This one makes sure that you see the proper voltage that the ECU wants and I'd rather go with this style if possible.

Post up any experiences you might have had and if you'd reccomend one method over another it'd be much appreciated and where I might find one. Thanks!!!!!