Do Hi-flow cats actually give hp increases?

its a simple question, I and I guess the answer should be “yes”

I really am just curious

if I go and buy a hi-flow cat, will I free up more hp, and make the car faster?

and what are come reputable aftermarket cat companies?

well you have to first think about the state of your cat you have now! If you ahev the origional and your car either ran ritch and or you used thoes carbon cleaning agents or fuel injector agents you could have heated up your cat too much melting hte inside and cloggin it up thus even a new stock cat woudl “free up hp”. However I bealeve the simple factt hat the cat is less restrictive is what gives you teh hp for the exuahst velocity gets to stay at a higher rate! However thepiping and diameter of the cat is also relative! If you go to big then you might actually not get the best results as well too small = too restrictive!

There was a test done on honda tech if you do a search on high gflow cats shoudl find the #'s but as I recall carsound cat was right up there with a test pipe in the flow charecteristics but if everythign else is stock and your cat is runing fine then no real use to replace it! However if your cat is failing it woudl be a nice way to free up some h/p and as wellget your car in good working order! While your at it you might wanna check to make sure your 02 censor is good…might just opt to change it while your there actually!

anyways best bet ebay a carsound cat and get flanges welded on and tada! cheapandeasy fix!


I haven’t checked my cat, but it does have 220,000 kms on it, and I just threw in a b20

I’d like to make sure it was flowing as well as it can

I’l check out HT and carsound…

I checked car-sounds website

and have no idea which one would fit my teg

Hey man, i haven’t done a dyno test or anything but i bought a basic high flow cat off ebay. I put it on and I noticed a definite gain in hp, but my stock cat probably has around 200,000 miles on it, so it might be clogged up. I ended up putting my stock cat back on because it was way too loud for me. I have a b16 with dc header,thermal cat back with no resonator. I just got a magnaflow resonator put on and a tsudo n-1 style mufller and my exhaust really quieted down. I’m probably gonna put it back on soon, and it wont be as loud as before. i gotta keep them cops off me as much as possible. But if i were you i would buy one, because most likely your cat is not performing at its best.