[Isphius]

If you just want to pass emissions, get a stock one from the factory(lkots of $$), and take it back out and replace it with a pipe after you pass. You can do this every time you want to get emissions tested. But for one your going to leave on, I would suggest something cheaper, like metnioned above, becuase you will be replaceing it more often. I also hear those metalcat cats are good stuff, I would trust them.