Opinion on replacing Cat or Cats on Firebird

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89 Firebird Formula 5.7 350 TPI. The cats have worn out on the vehicle and I have a small exhaust leak on one of the pipes. I am debating whether to use a Flowtech Y pipe and only use on high flow cat or to stay with the original configuration, using two cats. Does any one know if I will get more performance using one cat or keep the orginal configuration. I still want to keep the vehicle street legal.

posted by  fourriversbear

You will definatley get more power from using a single high flow cat than two restrictive stock cats.

http://www.jegs.com/webapp/wcs/stores/servlet/CategoryDisplay?catalogId=100 02&storeId=10001&categoryId=20921&parentCategoryId=10251&langId=-1

Plenty to choose from. Most are $79.

posted by  thunderbird1100

I thought you'd get more power from duals then you would from single exhaust (maybe just get 2 bigger/less restrictive cats?).

posted by  car_crazy89

That's not what I was thinking... The most ideal situation is (Still using cats) is have TRUE duals all the way from the headers back, using 2 high flow cats and two mufflers (keeping it legal). I was just suggesting doing a Y-pipe from the header's end to a single cat (something big like 3" in/out), then you could put it back out to duals or go single, wouldnt make a difference really at that point.

posted by  thunderbird1100

Thanks for the info, I was thinking the same thing. The stock configuration really seems funky. You have two pipes and two cats then a Y after the cats to single pipe to one muffler with dual exhaust. Pipe is 2.5. I am not sure I can put a 3" Y back to exhaust manifold. I really don't want to put headers on at this time because that would mean reconfiguring the smog pump. Thanks for the website I will check it out.

posted by  fourriversbear

Oh I'm sorry, I thought TRUE duals were being used, in that case then your idea would be better.

posted by  car_crazy89

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