Pros & Cons of cat gutting.....

[Unit 5302]

The catalytic converters have platinum, which is a catalyst to complete the burning of any raw fuel being dumped into the exhaust. That's why they get so crazy hot when you're running too rich, and they plug with carbon and other byproducts when you lack enough outside air being pumped from the smog pump.

Yes, a well tuned car can pass emissions in most cases with no cats because a car in excellent tune will not have a lot of unburned fuel going out the exhaust. I've seen it done before several times. My dad had a 1978 Lincoln Town Car with the 460. The cats were all hollow and every piece of emissions equipment on the car had been disabled. It passed after a run up. Keep in mind, it got 8-10mpg in town and 13-15 on the highway. It burned a LOT of fuel. That being said, a 5.0HO with it's aggressive camshaft really needs to be running great to do it.