OK so sometime next week my Greddy Evo should be arriving. :yay: Over Easter weekend i'm going down to jersey to install it with a friend. He suggested the idea of putting on a high flow/performance cat at the same time cause he could possibly get a deal on one.

My question is, would the addition of a performance cat cause the loss of too much back pressure....therefor making the car slower? Or would it help since I am getting a new exhaust system? I have a 95 EX Sedan 4 banger

Also...would torque be affected in any way?

 

Well one thing you need to know is that they are illegal and when emissions come you need to take off the cat and put the stock one back on. So make sure to keep the stock one. But im not sure on the back pressure part. Sorry.

Jon

 

I thought they were only illegal in California due to their higher emissions standards?

 

Well I know they are illegal here in Oregon too...

 

highflow cats are illegal on OBDII vehicles in cali and probably other states that are very strict.

otherwise if you use a carsound cat and since you are OBDI you should be fine.

 

Catalytic convertor that is a high-flow model is fine, and won't affect backpressure, just speed up the process of removing exhaust from the chambers. As for legality, those are fine, so long as your exhaust isn't over 98db I believe after it is installed.

Test pipes will likely cause more harm than good, they just make a whole #@$@ of a lot of noise...that's my adivce

 

So the sound of the system may be affected? I definately don't want it to be LOUDER than it should be.

Thanks for the replies.

 

High Flow Cat. = Louder Exhaust

 

my apexi ws is still quiet with a carsound cat. my old exhaust got very raspy and annoying though after the high flow cat.

 

Was the high flow cat. on your last system made bty Carsound? Many "high flow" cats that places sell are crap and are just cheap glasspacks or even test tubes... which will make your exhaust sound horrible. IMO Carsound is the only way to go. And you can get a universal 2.25" one for under $100.