They dont do the tail pipe thing on OBD II + models here in nashville, at least not on mine... They just plug in the port..

I think if i ever got a stroker motor up and running I would def change the stock cat, but not hollow it, I cant afford a fat "Fix it" ticket. I'll just go high flow.. like a 350 $ cat or something... what yall think?

Would the O2 sim fool the emissions place?

It's my understanding that when they plug into the obdII port thet they are relying on your downstream sensor to detect co levels. So yes, unless of course you get some over zealous dudley do-right that crawls under and finds the simm.

Hmm... Yeah that would **** me off all to hell if someone crawled under the truck to find the sim... I would rev it up while he was under there