Hi Flow Cat selection help
 

Hey fellas just a question.

I was browsing http://www.hottexhaust.com/ as esguerra gave it good reviews and I'm in the market for a 2.5" hi flow cat.

There seems to be A LOT of different types of 2.5" hi flow cats on the site. I see "Magnaflow Spun Metallic Substrate" and the Universal ones. I'm assuming the Universal ones are pretty much what I need. In universal I see one's with and without a o2 sensor input.

Would you be able to point me in the right direction in which one I should be getting? Searched but failed :( Thanks.

Specs: 1999 RS, RS*R Exmag Cat-back, DC Sports 4-1 2.5" Header.