There is a flat green[cic] wire between the body and the begining of the b-pipe I think. Mine is torn out for some reason. Does anyone know what its for there? Some kind of ground perhaps... Would it hurt performance if its disconnected or anything else?

 

it is there as a ground but mine broke once when i disconnected my cat to put in my short shifter and then again, i dont know when. i have noticed no difference in any of the vehicles performance or behavior. if it were really imprtant nissan would have made it much stronger and probably insulated. (so it wouldnt rust out so quickly)

 

As matt said, it's the catalytic converter ground...and pretty much everyone who lives where it snows has it loose (the bung for it rusts out)....anyhow, according to my dealer it doesn't need to be fixed since (obviously) the cat is grounded through the rest of the exhaust system that is attached to it (!)....

 

i removed mine. its sitting in my house connected to the cat