Hiflow cat Question

[trust068]

my cat is dying and i need to smog my car soon, so i need to replace my catalytic convertor

1. For people who had highflow cat, do you notice any gain? Can you share your experience (with brand, diameter, price paid..)

2. For CA owner, do you have trouble to pass smog? what is your NO index number and what was your mileage?

3. I have a RSR catback system and i am not sure what diameter of catalytic convertor should i buy. I am thinking get carsound 2.5", what do you think about it?

thanks alot

[miked808]

I noticed a slightly deeper tone it the exhaust note. The Top end was also improved, remember every restriction removed just compliments your other mods. I went with the 3in. Magnaflow good flow and if you went Turbo in the future you wouldn't have to worry about swapping it out. Got it for 80 bux online from a Truck Exhaust Co. Matter fact I liked it so much I put Two on my Silverado as well.
Modified by miked808 at 2:13 PM 9/10/2005

[1991S13]

I got a Catco highflow for around $100. The diameter was 3 inches, I had to use a reducer with a flange on it so it would bolt onto my exhaust.

I changed the whole exhaust system at the same time so I don't know if it made it any louder than it would be with the stock converter. It was also at the same time I did my manual conversion so of course the car was a lot quicker when I got done with it, lol.

In past threads I have read that highflow converters won't pass emissions. My car hasn't been tested since I changed it so I don't know from experience. Search for those older threads and maybe you can find the answer.

[trust068]

thanks for above responses. my civic with integra LS motor still pass smog with random technology hi flow cats, so i am curious if it is true.

So If i want it to pass smog, i would have to get oem spec cat?

[miked808]

You can pass emissions with a High Flow Cat.

[180fan]

Depends on where you are. Random Tech are 3 way, Catco's are 2 way. If you're in an area that tests for NOx then get the Random.

[trust068]

I think i am gonna go with carsound 94109 which has the function of 3way cat and it is in very good price. but it is 9" long, does it fits? I have a 91 240sx, the cat is weld on or bolt on? thanks

http://www.car-sound.com/catal....aspx

[trust068]

btw, i cannot check the cat in my 240sx because i left my car in my friend's yard, i dont have space to park it yet.

[trust068]

bump.....the oem cat is weld on or bolt on? any comment for the carsound cat with "3way function"???

[NateDogg]

The cat is a bolt-on. You'll need flanges welded on that particular cat to have it work for your 240sx.