So.. the maxima's exhaust broke the other day, and when I crawled under to look at it, the flex pipe that connects the y-pipe and cat has fallen off. Essentially im running open headers with a down pipe... I guess? The cat i believe needs replaced since the O2 sensor blew out and there are no threads on the sensor anymore, it is kinda stuffed in there however. Looking at the bolts on the entire system there are no threads on any bolt except the clamp which looks as though it has been replaced recently. My question is should I buy another flex pipe and say whatever, or should I replace the entire system? I have been pricing parts to replace the system on ebay, and of course the only pipe i haven't found on there is the one that broke.. I found an ebay cat for between $50-80, and two twin loop mufflers for $63. just need all the connecting pipes, a replacement y pipe is 225. Thoughts? Its really loud now and pops and crackles when slowing down. Was cool at first now just annoying.