Basically, I want to get a y-pipe but I don't want to get a hi-flow cat because of the noise and lack of a heat shield. So, if I were to get just the Y-pipe, would I still get most of the power increase? Or is the custom Y-pipe obsolete without the matching Cat?

 

The OEM cat has a 2.5" inlet and outlet. This will match right up with any Y-pipe or cat-back you get.

 

Say I leave the catalytic stock though, and get the custom Y-pipe. Would I still receive the claimed power gains from that y-pipe, or would I need a hi-flow cat to get the full benefit.

 

Yes, replacing the stock y with a aftermarket loses the two pre-cats from the system so you still get great gains with or without a supposedly high flow cat.

I haven't had personal experience with any high flow cats, but from what I've read on the .org they have never proven to be any more effective or less restrictive than stock for the price you pay..

 

my stock cat is going bad and im looking for a hi-flow cat as a replacement. from what ive read it seams that they are a good replacement for stock when the stock one goes bad, they are pretty cheap but dont add much power.

 

Yeah I have one. A magnaflow I purchased from Warpspeed. I also have a WS y-pipe and a 2.5" cat back. The high flow doesn't add much power at all, however it is a great alternative to buying a stock cat. Mine was bad, so I skipped the $300+ dollars and went with a $100 high flow. If your stock cat is still good then keep it on. The inlet and outlet diameters match up perfectly with an aftermarket Y and a 2.5" cat back.

 

thanks everyone! Looks like I'm going to get just the Y-pipe since my stock cat is good.

 

yea i am in the same boat my stock is clogged up. i am going to purchase the warpspeed, cause as far as i know it is the nly one that passes emissions

 

i had a hi-flow cat when i was SC'd and it made some difference but not much, and when i took out the SC, i left the hi-flow cat but i had that replaced and i no longer have a hi-flow cat and it made no difference at all to me.

 

are you passing emission with the cat from WS?

 

its minimal for freeing hp if your not turbo, if you need a new cat then just get one but its not necessary

 

if your stock cat is going... why not buy a high flow cat? you have nothing to lose, even if you have little to gain. other that that circumstance, i wouldnt buy a high flow catalytic converter. all high flow cats should pass emissions, i dont see why they wouldnt. unless they do not include the o2 sensor that connects to it.

 

I didn't pass emmissions with the high flow cat. I just took the smog test and barely failed. the "NO" (PPM) reading was just a shade to high. I don't know if that is directly due to the cat or not. Now I gotta find some sleazy shop and pass him money under the table to get it passed. Damn cali smog is tough. All I've got is a Y-pipe, high flow cat, and cat-back exhaust. THis shouldn't be this tough.

 

yea i would assume that a hi-flo cat would fail. me n my friends car both have noticible smells if standing behind the car.

 

I had an aftermarket Y-pipe in the past and failed emission bad so I switched back to stock. I did the driving around for ½ hour trick but it did not work for me. If both of you are passing emission in the past with the Y-pipe alone, I’m curious if high flow cat made it worst. If any of you folks live in CA, NY or NJ with stock Y-pipe and high flow cat, you may want to drop us a line or 2 on your emission result.

 

I know with FI you can feel a slight difference in the air flow when reving the motor.

 

My from the cat back everything is rusting slowly. Next month I will be replacing everything. Is a high flow cat neccessary, no.

 

well then a high flow cat seems pointless, might as well get a test pipe... you wont pass emissions with that but it gives you a lil more power than a high flow cat

 

yeah but the test pipe, sounds like sh*t, and gives no gains unless your boosted.

 

I have that smell,

 

can you just put the factory on for the test then chage it out after it.i live were you dont have to do this but i was just wondering

 

i have the hi flo cat and y pipe from warspeed and also have the apexi catback and i passed emissions with all of that

 

dude, you can do whatever the hell you want to your exhaust

 

Ahh yes, but the difference between Pennsylvania's smog test and California's is that Cali's is far more stringent, unforntunately. However, money talks and I will pay someone to "make sure" it passes. I have several friends who have done it before, but I wanted to see if my setup would pass on it's own.

 

get a $30 "test pipe" from warpspeed

 

with a test pipe you will have no chance of passing anywhere, especially here in cali where smog is the worst. most people who have hi-flows have passed, i just ordered one from warpspeed for $183 shipped.

 

I don't understand why some of you folks insist to get a test pipe to pollute air where you live and the planet earth for just 1 hp at most.


96stillen_max, is that with stock y-pipe and ws cat?

 

actually a lot of people have said they have passed with the ypipe and hi flow cat, just gotta be warmed up first

 

i have heard that only the Warpspeed passes.....hey go on ebay usually for 99+ shipping.

 

the WS ones on ebay for $99 are not CARB approved which means us california guys gotta buy the $175 ones from WS.

 

Is that what the difference is? I bought the $100 high flo. I should of bought the other one. Oh well, it doesn't matter, I'll get around it soon enough. Anyone want a test pipe? I still have mine I got from warspeed. I used it for one day only. Anyone want it for cheap?