When I grabbed my catback the pipe from the flange forward was cut so the flange was intact. It was a N. Tex car so the corrosion wasn't bad and the bolts came right out. Now on my car the corrosion was so bad the bolt heads were useless and the ends with the threads were pointy. Cutting wheel took the heads off and the flange seperated. Bolted the replacement in no issues. My catback was rotten like there was no tomorrow and the one I grabbed still looked new. Although if you go that route I suggest using a truck to take it home. It was too long to fit in the bed so I had the resonator end sitting over the cab with the muffs by the tailgate.