2003 expedition smoke from exhaust

I just cut my cats off my expedition, and ever since then there is smoke coming from the exhaust only when it starts and when you Rev it. When I drive there is no smoke coming from it, and when it’s at idle there is also no smoke, although it does have an odor, that I can’t quite explain, the oil is fine and there is no signs of leaks, and the car isn’t over heating at all. Is there any explanation why it started smoking after the cats were removed?

I’d say you were already burning oil, and the catalytic converters were “catching” the oil exhaust.

Removing the catalytic converters is not a good idea, by the way. And illegal.