On ‘popular but wrong’, I will be bringing you a few popular opinions on car tech with explanations why they are wrong.
CATALYTIC CONVERTER
On this side of the globe, the catalytic converter has gained a very popular alias - ‘the Indomie’, after Indomie noodles because of the noodles like shape of the converter metals. In other worlds, it is simply called the ‘Cat’.
There is a popular believe and claim that the Cat/Indomie improves fuel economy. I say a big Wrong to that. The Cat is not designed to, and so doesn't improve fuel consumption. The Cat is designed to remove poisonous gases and elements like Carbon monoxide and Nitrogen from the exhaust gas. Thus, its main function is to reduce excessive air pollution. It does this by reacting with the gas as it passes through the exhaust pipe. Or more specifically, it facilitates the
reaction, that’s why it is called a catalyst. One of the end products of this reaction is water which might be seen dropping off the exhaust tip at times.
There is something else in the exhaust system which functions to measure the composition of gasses passing out the exhaust pipe. It is simply called the sensor (or a variation of that). It sends the data to the on-board computer or ECU which in turn adjusts the air-fuel ratio for optimal combustion. So the sensor(s) directly contribute to fuel economy. It is fitted after the exhaust manifold and before the Cat. Some cars do have a secondary sensor placed after the Cat which also feeds the ECU its data. But this second sensor doesn't determine the fuel economy of the car, it measure the amount of carbon emission per mile or kilometer for that cars as it is expected that the Cat would have cleaned up the gas as much as it can before it reaches the second sensor.
Just to add, the Cat can be removed without touching the sensor (I've not heard of an otherwise assembly). This is one of the things that happens in car upgrade workshops were stock cars are upgraded for higher performance. The cat is entirely removed, at the expense of environmental pollution because it is a major obstruction in the exhaust system and any obstruction in the exhaust system reduces engine performance. So if the cat has anything to do with fuel consumption at all, I will say it increases fuel consumption by a small bit as the car has to do more work to push out its own gas… You know how much work you have to do when you are sitting on a comfy couch and you have to push out your own exhaust gas compared to when you are standing freely and you just let it out?

Source : http://101carsense..com/2013/07/popular-but-wrong.html

Can confirm, cat deletes don't directly affect fuel economy at all.

HeavenlyBang:
Can confirm, cat deletes don't directly affect fuel economy at all.

Can 02 spacer work in case of faulty Cat?

seanfer:


Can 02 spacer work in case of faulty Cat?

Yep. Remove the cat and install spacers. It'll fool the ECU into thinking a cat is present.

HeavenlyBang:


Yep. Remove the cat and install spacers. It'll fool the ECU into thinking a cat is present.

But what about the consumption of fuel?

Any damage to the engine after this modification?

dicksonadams:
Any damage to the engine after this modification?

No. Only thing that can damage your engine is driving with a damaged cat.

Running without cats on my ES350. Only downside that it is louder .

Inception:
Running without cats on my ES350. Only downside that it is louder .

How is that a downside?

HeavenlyBang:


How is that a downside?

Dude!

Its a Lexus!

I love my cars pindrop quiet

On some Cara, the increased noise levels can be quite disconcerting.

Replaced the one on my big for nothing. It was unbearably noisy for long journeys.

9icetoo:
On some Cara, the increased noise levels can be quite disconcerting.

Replaced the one on my big for nothing. It was unbearably noisy for long journeys.

I bet you'd hate my car.
The stock exhaust is already loud, taking off the cat just made it a lot worse.

Aunty Radautoworks come & see testimony on cat delete

#TeamNoCat

Team 02 spacer , no noise, luxurious with my tuke tuke vibe and Honda

thebigkendo:
Aunty Radautoworks come & see testimony on cat delete

#TeamNoCat

I knew you'll be here

There was a time when a law was passed that enabled law enforcement agencies inspect exhaust gases for pollution. I really can't remember the details as I was still quite young. Hopefully, those days will be back again. You guys should stop polluting our environment

thebigkendo:
Aunty Radautoworks come & see testimony on cat delete

#TeamNoCat

Carry on. As for me and my house we will use the cat.

Now Okon is now more confused!

HeavenlyBang:


I bet you'd hate my car.
The stock exhaust is already loud, taking off the cat just made it a lot worse.

I'd love the note from the outside but wouldn't want to be inside on a four hour journey. I might go deaf before I get to my destination.

Nice writeup.
But from deeper research, it all depends on the car and the extent to which fuel economy is affected.
It also depends on where fuel economy is affected. At low end or high end. Check how the cat affects low end torque and scavenging.
Again, some cars use after cat sensors for fuel adjustment. It depends on the extent to which it does that. Some up to 10%, some 30%.
Regards.

Once your 02 sensor is bad. If u like have catalyst or not. Your mpg go drop maybe to 10mpg. Plus driving habits. But with catalyst converter your will get fair miles.

EngRichie:
Nice writeup.
But from deeper research, it all depends on the car and the extent to which fuel economy is affected.
It also depends on where fuel economy is affected. At low end or high end. Check how the cat affects low end torque and scavenging.
Again, some cars use after cat sensors for fuel adjustment. It depends on the extent to which it does that. Some up to 10%, some 30%.
Regards.

All depending on the design and what the engineers wanted to achieve. One size never fits all.

Exactly!

AutoMoTech:


All depending on the design and what the engineers wanted to achieve. One size never fits all.

rationalmind:


I knew you'll be here

There was a time when a law was passed that enabled law enforcement agencies inspect exhaust gases for pollution. I really can't remember the details as I was still quite young. Hopefully, those days will be back again. You guys should stop polluting our environment

Till does days....
I don't see any reason to spend over 50k on Cat replacement, when it has no "negative" effect on MY car...
I will not purposely delete my cat.. But if the Cat goes bad(which will most probably happen due to our fuel), or gets stolen, i will not replace it

thebigkendo:


Till does days....
I don't see any reason to spend over 50k on Cat replacement, when it has no "negative" effect on MY car...
I will not purposely delete my cat.. But if the Cat goes bad(which will most probably happen due to our fuel), or gets stolen, i will not replace it

This cracked me up

When dru sees it, he'll be like "This is why I don't buy Nigerian used cars

HeavenlyBang:
Can confirm, cat deletes don't directly affect fuel economy at all.

Please how can one get the O2 Spacer.... I'm in Port Harcourt.