I have been learning alot about cars since I got my cobalt 3 months ago, but still have no idea what a "cat" actually does. Help me out

1. What is a cat and what does it do.

2. What are advantages/disadvantages of having a downpipe with/without a cat?

3. What do they mean when they call it a "cat-back" exhaust system?

Thanks for the time

 

well to answer #3, a catback system is a aftermarket exhaust system that runs from the end of the downpipe to the exhaust tip. basicly the whole pipe under the car that directs the exhaust flow to go through the muffler and out the back. catback replaces stock piping, resnoator and muffler and usually has a bigger tip. either get a brand name catback or go custom.

 

You will get flamed very soon for this question since you didnt search. But everyone was a noob once so Ill tell you what I know.

1. cat= catalytic converter
2. pros/cons I dont know
3. ^^^ What he said

 

1. Cat.

2. Removing the cat makes your exhaust much less restrictive...more air flow generally means better power, especially after you start doing engine mods. (pulley, tuning, etc.) Your car will be significanly louder with no cat, and good luck passing any kind of emissions where they use a sniffer.

3. Any "xxx back" exhaust means from that point back. Cat-back, turbo-back, axle-back, etc.

 

But why do they call it a "cat-back" then? I am aware of the parts involved and replaced. Is it just the standard verbage that everyone uses? Or is there an alternative to cat-back?

 

1. A "cat" is a catalytic converter. An air pollution abatement device that removes pollutants from motor vehicle exhaust, either by oxidizing them into carbon dioxide and water or reducing them to nitrogen.

2. The advantage of having a cat is producing low emissions and it will help keep some back preasure for low end power. It also sometimes eliminates a raspy sound from exhaust.

3. A cat-back exhaust is basically that. It starts from the cat (It doesn't include the cat) and goes all the way to the tip.
So it's some piping and a muffler from the cat to the tip. As apposed to a full exhaust.

 

Why do some people choose to go without one? Or is there even an advantage to that?

 

i guess you didnt read

 

Well if you don't have a cat you will produce a little more power because there is no cat in the way of the flow of the air.
You won't pass emissions if you don't have a cat. Some guys don't care they want the power increase from not having a cat. Not having a cat will really only yield about 2-3hp.
I recomend you get a cat.

 

Thanks

 

No problem! Happy moding.

 

not entirely true. you may lose power also. some setups need some kind of back pressure.

 

Already mentioned that to him.

 

1. MEOW! -- household pet...right above the rat on the species ladder.

im sorry, had too...anyways, what they said

 

Show me one setup in the whole world that makes more power using a cat. Just one.

 

Like Tom said, cat-back refers to changing all the piping after the stock cat, from the CAT BACK. They also have turbo-back exhausts, all the piping from the turbo back. Axle-back is usually just the muffler. Header-back, downpipe-back, engine-back.