Mustang Boards - selling car???

I believe my car will be sold as of next friday. now for the question, im sure alot of ppl on here have either bought or sold a car with an o/r mid pipe on it. I have an o/r x on the stang and the guy im selling it to lives in PA, do i need to write somthing up to cover my own ass saying that with the current exhaust the car is not street legal? i am giving him the stock H with cats with the car but he will be buying it w/o cats, i dont know if this is ilegal or not or if he can come back on me if he gets in trouble before he swaps the pipes over for emmisions...