HighFlow Cat vs. No Cat

[SuprSpdDB7]

What are the advantages of using a high-flow cat versus using NO cat whatso ever. my exhaust is getting put in Monday and i wanna know which will benefit me more.... I found a place that WILL put on an exhaust system with taking OFF the cat... what should i do???

[GrdLock]

I'd leave the cat on personally. First, it helps keep a little backpressure going on. Second, it'll help make your exhaust so it's not super loud. (a bad loud)

[Ttop34]

Not sure performance wise but after it was all done and my SES light is on even with an o2 sim, it would have been about the same price either way I went. I spent way too much taking the cat off and making it 3" all the way back. The sound above 3,000 rpm's isn't the greatest but it's pretty powerful now.

If I had it to do over again, well, first off I would have either built a cat back system with the 3" Dynomax I pipe and a flowmaster muffler or got the American Thunder cat back 17143 that includes the S pipe and had the shop cut off the end of the cat and make a 3" out cat. I would have also had them put a cut out before the cat which was remote opened/closed for racing.

Dynomax I pipe: $97
American Thunder 17143: $266.99
Cut out with remote: $100(I think)
3" S pipe and taking off cat and o2 sim: $150(if done by yourself like I did)

Oh yeah, yes the stock cat can be addapted to a 3" outlet, just look at my site to see where to cut with a saw and then weld it back. You do run the risk of melting that ceramic stuff in there though.

[jrcamaro96]

I have had no problems what-so-ever after I have taken off my cat. I did lose some back pressure but I can deal with this for now. I have now gained more up top after removing it though.

JR

[RacerJ]

I would leave the cat on, just put on a high flow. Reasons being:

- Chances are good that your car will run better with the backpressure the cat will give it.
- Running without the cat is illegal.
- You'll fail smog inspection without the cat.
- No real performance gain over a high flow cat.
- Some people have problems of the exhaust smelling and sometimes discoloring the car where the exhaust exits when they have taken off or gutted the cat.

Just go to www.SummitRacing.com and pick up a Catco.

[SuprSpdDB7]

alrightty...i just ordered the catco high-flow from SummitRacing.. i will let you all know about my plusses and minuses... when i get the exhaust on i will probably post some sounds if i can...

[Ttop34]

<blockquote>quote:</font><hr>Originally posted by RacerJ:

- Chances are good that your car will run better with the backpressure the cat will give it.
- Running without the cat is illegal.
- You'll fail smog inspection without the cat.
- No real performance gain over a high flow cat.
- Some people have problems of the exhaust smelling and sometimes discoloring the car where the exhaust exits when they have taken off or gutted the cat.<hr></blockquote>


Not entirely disagreing with you, I would have got a high flow cat if I wasn't convinced that I would have got an o2 sim anyways.

About it running better with a cat, define better. It will have more low end power to run around town but still has plenty without one. The gains from a high flow cat are nothing, the only thing you get is the gain from moving up to a 3" outlet which you can chop off the stock one and weld a pipe to, I did but don't have anything in my cat.

Running withoug a cat is illegal, this is true and I'm probably causing some poor animal to have cancer or something. That's not exactly a part of it I'm proud of.

Smog inspections? What's that? We don't have that around here. Nobody ever looks under the car when you get it inspected either.

As for discoloring, think that will happen with or without a cat, your car is still doing to put out a little black stuff and some liquid that will some how ruin stainless steel exhaust tips, just look at Trans Ams that have those.