Anyone run high-flow Cats to reduce hydrocarbon exhaust smell?

Having the mixture as close to stoich' as possible at part-throttle as opposed to lean allows the cats to work most efficiently in the chemical reaction aspect. The balance of different gases is such that the cats are able to convert the max amount of it to less harmful stuff as it flows through, and not burn up at the same time. They're pretty sensitive devices, if you're burning oil/running rich/leaded gas etc. over time the element inside gets coated with crap basically and stops working.