hi,I have a high flow cat and I was wondering if I should put it on my 91 civic sedan or keep the original one on?

is there any pros and cons of a high flow cat?

thanks

 

Most every high flo cat will give you a performance gain as you will have reduced exhaust back pressure.
The downside is that not all of them are constructed to give you a passing result for smog.

The stock 'honey comb" core works fantastic, but is expensive - $300.
A cheap one may use ceramic plate core and doesn't work nearly as well as stock = smog fail.

 

thanks for the reply.... i live in ohio and we dont have any emissions testing here so it wont matter if it dont pass a smog test right? so pretty much if i don't want to hurt the enviroment then keep the stock one on but if i want performance gain then go with the high flow.

thankyou again for the info!

 

...or just run a straight pipe ("test pipe")...