i am lokking 4 high flow cat. i don't know which brand to go with. i seen obx on the ebay for about 48$ . is obx good ? and how many hp will i gain ? what is down side of having aftermarket high flow cat bolt on ? thanks

 

I'm using an obx high flow cat right now. Works fine with my setup.
Might swap it out for something else later down the road. Plus it's not too expensive.

 

those ones are basicaly straight pipes, if u really want a working high flow cat, pick up a carsound, i jus bought mine for 60 shipped form ebay last week, costed me 40 to add flanges and bolt up to my exhaust

 

friends experience with obx hasn't been good. if you can, save up and get a better cat. i run stock, so i couldn't help u with a brand.