Hey guys, my 460 seems really dirty all of a sudden..My engine oil is instantly dark when right after i change the oil. I also am suffering from 5-6mpg as well, I feel like my truck is running very rich. I had my catalytic converters gutted a few months ago, would that have ruined the o2 senors or something? I think the unburnt fuel is getting left in the oil, hence the dirty oil. I also think its fouling my plugs, and if it is running rich, its killing my MPG. I don't know, would this hurt the motor running this way. Also, at idle, the truck goes threw stints where it idles extremely low, almost as if it its going to shut off, making me think its got way to much fuel getting dumped into the cylinders./ What do you guys think? I would love some opinions.