ok, so my strange problem was a clogged cat... so now i cant get the stupid thing off to swap it. i have even busted a 3/8" drive ratchet trying.
anyone know if a regular blowtorch will get the nut hot enough to remove it? my friend(whos a mechanic) said to use a cutting torch, but i dont have one. also will it hurt anything to use a torch on the top nut or will the heat shielding protect the car?

thanks in advance!