hey guys i was wondering what was best to run on an sti high flow cat or catless downpipe. i wanna run catless but ive heard bad things what do u guys think

 

run a cat not as smelly and also wont be as loud. its only like 5whp for a cat. So that can be made up with good driving pde makes a great catted downpipe

 

go catless

 

Catless dp on the STi gives you problems. If you dont mind the hassle of fixing the boost creep, then might as well go with the catless. I'm not sure if a high-flow cat will give you similar problems. A search might help if you want more in depth info...