would my car run like crap without a cat?

[Juicy05]

and after awhile your exhuast gets a whole shit load of carbon buildup, ten times worse than normal and spits black shit out of yoru exhuast........i get pissed

[icE_x]

lol mine does that because it burns oil lol

[BiGwiLLswiLLy]

well if u are runnin turbo then go no cat and bigger exhaust but if it you were runnin all motor then jus leave it cause u need the back pressure anyway, plus in a all motor car guttin the cat wouldent make a diffence...

[Kven]

Originally Posted by BiGwiLLswiLLy

well if u are runnin turbo then go no cat and bigger exhaust but if it you were runnin all motor then jus leave it cause u need the back pressure anyway, plus in a all motor car guttin the cat wouldent make a diffence...

back pressure is bad in any setup. the word youre looking for is velocity(you want the exhaust gas to move as fast as it can without backing up/backpressure); i think it was stated above.

[KinkBykr]

1)It makes your car stink
2)the tiny differnce is not worth putting that crap in the air
3)it's louder, so more tickets from cops saying your recklessly accelerating, belive me, happened to a friend

BUT if you insist there are valves that you can buy to put in your exahaust before the cat, but really, for the $$$ you would buy that for, eh, not worth it, use the couple bucks to buy something usefull

[BiGwiLLswiLLy]

no backpressure is needed with out it N/A motors run like shit without it disconnect ur exhaust at the cat n drive you'll see it will move like a turtle...

[Kven]

Originally Posted by BiGwiLLswiLLy

no backpressure is needed with out it N/A motors run like shit without it disconnect ur exhaust at the cat n drive you'll see it will move like a turtle...

do you understand the difference between backpressure and velocity? its proven that backpressure is bad for your engine; people remove their cats, which is obviously restrictive and creates some backpressure; and noticed some hp/torque freed. If there's any backpressure; the engine would have to work to move it out; while gas moving at high velocity will actually pull some gas out of the chamber(and pull some intake during overlap, aka scavenging). When you remove your exhaust, you have no or very slow gas velocity; and if you noticed lots of N/A cars with large pipes tend to lose low-end hp; due to decreased low-rpm velocity, while small pipes work good in the low rpm range but choke high-rpm power.

a perfect exhaust/header combo would have the highest gas velocity without causing pressure buildup/backpressure.

edit: found something that shows increase in backpressure(in this case, a cat) will make you lose some hp on a NA engines(not much HP loss, but its still result of increase resistance/backpressure, aso on this engine it started running lean with the introduction of the test pipe; so more fuel would need to be added; we all know more fuel=more power but decrease in MPG):
This is on a B20Z, Magnaflow Street exhaust, Blue=with cat, Red=without.

[BLU CIVIC]

no need to pull out the charts and graphs mr professor b/c the topic of backpressure has been discussed extensively...it all boils down to wether removing his cat is worth the extra 2hp or not...i still vote nay

[Purplcivic]

mine doesnt have a cat, got no problems, 40 mpg on a straightpipe, smell - i dont smell shit, just gas, noise - not really too loud, engine breaths well - would you like to have a congested nose? Yes, there is a significant power increase.

[Kven]

Originally Posted by Purplcivic

smell - i dont smell shit, just gas

thats the smell...