What does a catalytic converter do?

>is it possible to create a sleeper where when I'm daily driving, the car wont back-fire, but when I actually try to go fast or hit high rpms, it'll shoot out fire?
Simply removing the cat won't do that.

Ok, when does a car back fire cause of the removal of the cat?

Burns off un burnt smell. When you drive behind an old piece of shit car without them, you'll know.

>remove the CEL bulb
>get a car that was made before catalytic converters
These are your choices.

Converts NOX back into O2 and N2. Generates quite a bit of heat as it does so too. Does shit for MPG and performance. In fact your car will run better without it. But that's illegal. So don't do it. Or do it, but keep it a secret. You know, off the internet?

The catalytic converter removes unburnt hydrocarbons and carbon monoxide from your exhaust. It contains a fine mesh coated in platinum or other noble metals, which catalyze the combustion reaction and complete the combustion process to yield water and carbon dioxide.

Modern gas engines don't produce significant amounts of nitrogen oxides. Diesels do, so they have a selective catalytic reduction unit which reacts NOx with urea (in the form of diesel exhaust fluid) with the aid of a different type of catalyst to produce nitrogen gas.

more fuel than air in the system causing the excessive fuel to go boom boom out the poppy hole

converts the catalytic, dumbass.

Backfires are generally caused by not having a catalytic converter because unburnt fuel ignites in the exhaust rather than being vaporized by the cat.
This is generally because after removing the cat what ever engine it is will be running very lean (more fuel than it can use due to air pressure sensors in the exhaust sending confusing readings back to the computer)

>lean
Did you mean rich?

A professional tune. The second o2 sensor is purely there just to make sure the cat is there. A tuner can easily make the ECU forget about it.

Reduces CO from the exhaust so people who stand behind your car don't fucking die. Also helps some other emissions bullshit but who cares.

Yeah I did. My bad user

>falling for the high flow cat meme

ALL cats are "high flow" these days

>High flow cat
Literally impossible

It converts catalyics, catalyic being an old English word basically translating as crazy cad lady. The type of person who cleans there cats the way they preen themselves by licking them. The idea of fitting them was so mad because it increased fuel consumption that car makers desired to take the piss out of Margret Thatcher the UK PM who lobbied for them in the EU because of funding from the oil industry (you had to run a richer mix with the early ones than without to get the right gas mixture in the exhaust).

you aren't even me but yeah lol.

You're dumb.

Why would you replace it?
its for emissions at the cost of reduced performance, no one cares about emissions...

Put your catalytic converter back on.

If it runs rich as a motherfucker and the exhaust is hot enough. This is the dumbest idea I've heard of in a while. Even in actual race cars we try to tune for efficiency to reduce pit stops. Flames out of the tailpipe means you lost power and fuel economy.

Retards need to stop decatting. It doesn't provide anywhere near a significant performance benefit and causes a ton of issues on modern street cars.

>we

What if my car was manufactured before catalytic converters were common place?

I just removed my cats. Performance I would say it's maybe 3 whp in higher hp applications. I don't have any because I enjoy no cats sound better and my new setup hangs lower than stock so having even a low profile cat would be the lowest point on the underside. Also flames because racecar. Hoping to pick up a 2 step just for flames purpose

Question for carbr/o/'s.

Plenty of motorcycles pop and crackle like MAD after decatting because most emissions systems in motorcycles injecr extra air straight from the airbox into the exhaust stream to catalyze CO and hydrocarbons with help of platinum, rhodium and palladium in the catalytic converter

>phone posting
m.youtube.com/watch?v=E4Q9PRFWvgY
Listen at 0:26 ish, on decel it is popping alot, plenty of Euro 3 and 4 motorcycles do this because of the air injection meme. Why do cars not utilize something like this? More parts to break? Noise? Muh racekar feels?

I dunno why you're trying to justify decatting to me. Your logic is retarded if your only reason is sound and flames.

Cars have secondary air injection as well but only on cold start. Once the catalytic converter is up to temperature it reduces efficiency.

>Flames because racecar
>Maybe 2hp
>He doesn't even know if it made a difference
Get a load of this fucking moron.

when you remove it, there is a chance that your car will actually perform a little worse because something something pressure in exhaust piping

there is also a chance that your car won't work because electronics check if exhaust chemistry is right, and some cars just get down into safe mode without cat

there are also lambda thingie emulators that you connect to obd port. sometimes it works

Don't decat you shithead

>Retards need to stop decatting. It doesn't provide anywhere near a significant performance benefit and causes a ton of issues on modern street cars.
THIS.
Denying the climate problem is just plain stupid.
Having a guilty pleasure like driving a racecar, taking long showers, eating lots of meat, flying everywhere is just human. doing it all, as much as possible will lead to the inevitable: tax co2 emissions.

Costs a lot of money and gives the government money

user, just two questions:
-What is your rear bumper made of?
-Have you checked to see if decatting and the 2-step raises your exhaust temp?

Those are my 3rd and 4th reasons. First and second being cost and clearance.
People have dyno tested my same make model numerous times. There is a slight decrease, albeit small with cats, in hp. When you stop being a displacement you'll understand.

It's not even CO2. Decat means carbon monoxide, NOx, and formaldehyde emissions shoot up like crazy. All of it is horrible for you and everyone downwind of your car.

What did you do to your factory cat? And I'll bet money that your exhaust does next to nothing for power. Most factory exhaust systems are very carefully tuned these days.

underrated post

>mfw live in one of 7 counties in my state that requires cats and emission testing

I replaced my cat converter with a dog converter.

If that were the case, I would literally get a residence just outside the county.

LTs went on. Factory cat can not be fitted (2.5" vs 3" Piping). Sitting in the garage.
Kek headers have been proven to gain anywhere netween 20-25 whp.

Do those headers have to pass FTP testing? No? Then it doesn't matter. If you throw emissions out the window of course you can get more power, that's the whole fucking point of a catless downpipe.

For a street car emissions counts. If you can't make it pass smog and you smell like raw gas after driving it the car sucks dick. Stop with the backyard engineering and do it right.

That's exactly what I plan on

No shit sherlock, now what are catalytics?

can we have a good cat delete thread?
specifically how to properly tune to get added MPG and power

LOL fuck the environment it LITTERALLEY will not effect me why would i EVER care??

If you leave it running in the garage it will kill you.

VA?

I only decatted one of my vehicles because mine were clogged and I'm not paying the value of the car for new ones.

Car's going to put out the same amount of CO2 cat or no cat. The cat only converts the toxic acid rain/smog shit to less that's harmful.

> Flames out of the tailpipe means you lost power and fuel economy.

You don't know what overrun is or what causes backfiring/flames on down shift, Sit down child.

Decatting is good for your turbo, turbos hate the extra back pressure when they're trying to flow as fast as possible. Tune your turbo right and you'll get a much better overall engine performance. And I say "performance" excluding driveability and fuel efficiency. Unless you have forced induction or are going str8 racecar don't do it.

High flow cats are like banging your gf's bestfriend. It's great for the moment but later on you're gonna wish you gone without the extra baggage. The precious metals will run out even faster due to the large amount of hydrocarbons pumping through. Once they're fully used you've now got an exhaust restriction. So many wikepedia posts, but not enough people using critical thinking skills. Explains why we're all here I guess.

nigga u dumb
you dont want anything but the exhaust of a full combustion running through ur cat.

You don't understand that the engine has overrun happen naturally on deceleration.

>afterfire

dont you mean backfire you stupid fuck

I'm an idiot with cars so what do you expect? No mechanical knowledge = I just wanna get what's cool.

>smog
lmao not everyone lives in a shitty state like you do.

What the fuck is going on here? Where am I?

Welcome to Veeky Forums, enjoy your stay.
Remember, you are here forever.

I've done ECU tuning before. I have the data logs. Any remotely modern ECU will cut injection on overrun and a big afterfire on downshift is indicative of poor wall wetting/accel fuel settings.

>And is it possible to create a sleeper where when I'm daily driving, the car wont back-fire, but when I actually try to go fast or hit high rpms, it'll shoot out fire?

Legit the easiest way to do this is with an arduino, spare fuel pump and bottle of ethanol in the trunk.

>Hit target RPM
>Squirt ethanol into hot exhaust
>????
>fire

This, OP. Ethanol burns cleaner and you won't leave soot all over your bumper.

Kill code. That's it besides put cat in again. I'm lucky enough that my car has a single sensor before the cat

The best way to make more power out of an exhaust system is weight.

I shaved 24lbs off my car by buying aftermarket axlebacks. That's about a 2whp increase.