im sure the lack of cats but especialy no O2 sims is pissing the car off...

when you remove the cats you will have exces hydrocarbons emitted fromt eh tail pipes, more so than before anyway. the cat would have changed these to other gasses and whatnot, so that could explain some of the smoke and odor.

but back to the no O2 sims, right now the car thinks the cats are not working...im suprised it has not set a check engine light. i wouldnt even be suprised if the car is staying in an open loop, which would also explain excessive smoke, odor and the poor economy.

these are just a few qucik thoughts