Deleting cats... Can O2 sensors be fooled?

[bluex]

The PO of my truck removed my cats, probably for the same reason I decided not to put them back. A 5.7 vortec has two an a replacement assembly is around $500. It hasn't hurt a thing without them. No fuel smell an it still got 16 mpg stock....

 

[volunteerff21]

I have what's called 02 sensor extensions on mine. Pretty much same thing as a spark plug fouler. Been on for a year and a half with no issues or SES light.

Here's a link

http://www.ebay.com/itm/Oxygen-sens...t-Pipe-O2-M18-X-1-5-thread-size-/261297803163

 

[Horns]

Ok gotta ask!!!!! Why remove the cats. In a proper running vehicle the cats DO NOT hinder the exhaust. If they are starting to get clogged they will but not if they not. It has been proven time and time again on most street vehicles on the dump that removing the day does not hinder you numbers enough to even worry about leaving them in. Again this is in a properly running vehicle.

A cat will and does help cut down on the fuel smell that you most likely will get if it is not there. It helps burn the minute unused fuel/gasses that gets to the exhaust system.

A cat that is not clogged will not hinder your fuel mileage either.

So to all that just wanna remove them for the hell of it, I ask this..... Why? If it doesn't benefit you to do so. It will cost you, not much mind you but, to get a piece of pipe back up on there in its place. And aftermarket free flow style cats are cheep these days.

Ok I'm done steeling the thread you can have it back now.... lol.


Sent from what use to be a great country.

Cats take a lot of definition out of the exhaust. I've hit a cam, and I like to hear it.

I would also assume you've never seen the honeycomb inside of a cat. Exhaust getting through is like trying to pour water through a concrete filter.

But to your ?? What size is the exhaust you have that is true duels? I would rather keep a true duel set up with an h-pipe then have a single exhaust. A duel set up with a crossover pipe, no matter what style, equalizes the pressure better between the two banks and will let them breath better/more efficient letting you make more power in the long run.


Sent from what use to be a great country.

A y pipe will have the same effect.

~Via Mobile \,,/

 

[VorTecxas]

I removed my cats on both the Sierra (pre-tune) and Yukon, not to mention my three previous trucks. Never set the light off, and I never messed with the O2s

 

[Horns]

I removed my cats on both the Sierra (pre-tune) and Yukon, not to mention my three previous trucks. Never set the light off, and I never messed with the O2s

What year were they? TBI trucks only came with a pre-cat sensor.

~Via Mobile \,,/

 

[Parentnoia]

I've toyed with the idea of removing my cats but now I'm hearing rumors of TX doing emissions testing and that cats would become something that they inspect.

 

[Horns]

I've toyed with the idea of removing my cats but now I'm hearing rumors of TX doing emissions testing and that cats would become something that they inspect.

Gonna be a while, EPA is shut down.

~Via Mobile \,,/

 

[Parentnoia]

Gonna be a while, EPA is shut down.

~Via Mobile \,,/

I've been being told about the emissions thing for almost a year now though.

 

[great white]

When you next get the PCM tuned, have them turn off error reporting related to cat efficiency. It's simple simon easy to do. This effectively renders the rear O2 sensors useless. You still need the fronts for fuel trimming.

If you pop the O2's out after this, don't throw them away. They are still good and the same ones as the front sensors making them decent spares.

Be warned though: if you ever move to a state with emissions testing, you're hooped....

 

[AirmanSkee]

Like I said, I am only doing this as a repair for now. The exhaust I put back on my truck after someone tried to steal my cats was , but better than nothing. But now I got my hands on a good piece of 3" pipe off a CCLB with a nice Flowmaster on it for free. Only cost would be the sticks to weld that thing on.

NOW, once money falls from the sky and I'm not scavenging exhausts for free, then yes, I will do it right. I'm only asking this to save this:

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From happening again.

SO, can I Y pipe my small duals into this 3" single with flowmaster? Would it run right?