The mada brotha here Madahajimoto have JBA Headers anybody could tell me if taking out the Cats would create a problem to pass State Emission later
Thanks Club.

Yep, it will create problems.

......if taking out the Cats would create a problem to pass State Emission later
Thanks Club.
Uhhhhh, doesn't that like defeat the purpose of emissions??? I had a Camaro Z28 that I rebuilt with dual exhaust without the Cat and let's just say that I was lucky that I never got caught driving it on public roads.

It depends on your state emission laws and how they test the vehicle.
Visual they would fail, ODB check they could pass if you have a O2 sim that works.

You could always swap them back when comes time to smog it also...would be a pain to do though....but an option.

The mada brotha here Madahajimoto have JBA Headers anybody could tell me if taking out the Cats would create a problem to pass State Emission later
Thanks Club.
Yeah Bro, with you being in VA and your annual vehicle inspections, that would definitely be problem.

The mada brotha here Madahajimoto have JBA Headers anybody could tell me if taking out the Cats would create a problem to pass State Emission later
Thanks Club.

I would never tell anyone to do this but......i heard that you may be able to drill out the media inside the cat and reinstall and you'll pass the visual cause there still in place...but i'd never advocate that...:rolleyes:

I would never tell anyone to do this but......i heard that you may be able to drill out the media inside the cat and reinstall and you'll pass the visual cause there still in place...but i'd never advocate that...:rolleyes:

Thats not good to do at all and can even hurt the performance of any vehicle from doing that.

I would never tell anyone to do this but......i heard that you may be able to drill out the media inside the cat and reinstall and you'll pass the visual cause there still in place...but i'd never advocate that...:rolleyes:
We used to do that on older cars that were carbuerated but with the new ECU's and all of the sensors on today's cars, I wouldn't. During the '90's, I've heard some stories from people having to do everything from getting the ECU reprogrammed to replacing gaskets that were blown due to wrong readings from the pressure sensors. I'm pretty sure that overseas vehicles that do not require emissions, have different ECU's than we do.

Thats not good to do at all and can even hurt the performance of any vehicle from doing that.

Plus, it will probably piss off Al Gore!!!:D

How long has this been up?? My pre cats are gutted, as long as you keep them on you should be fine with visual, unless you fail and they will just point a Heat thermal gun on it and tell you they are bad. Unless he or she is a jerk and sends your suv as a gross polluter, you shouldnt have a problem finding out if its gonna pass or not, just check your smog tech out first... Should be no reason for you to end up @ referee unless you get pulled over and the cop lights up your cats with the ht gun. Then you can just tell the cop, man, I noticed the car a little louder and try to explain you didnt know they went bad. No perfomance loss here. A little louder though. Passing smog in my state?? I doubt it. If you do gut the cats out, gut the ones closer to the EM for that extra few hps. The pre cats are just to get the main cats hotter. Its not as essential as the main cats (torpedo lookng ones before the exhuast). Just make shure you run the car hard before your smog test...Stillen offers a emulator for ppl who dont care for cats. But you need to use their headers ONLY. For some reason the flow is programmed to their emulator. I dont know why they offer them though for because I have no problems with mil lights at all. I have the JBA's though. I wonder if thier flow is more agressive. I got connects at the delaership that are gonna overlook my exahust system and get my cats waranteed out, when my 4 years comes around. I just cant do it now for it looks kinda suspecious with only 6800 miles on her. Once again, no check engine lights here.

I am sure there are test pipes out there that you place instead of the cat. I have one for my drift car and when I need emissions, I just put the cat back on. You can try any local muffler shop to make you a test pipe.

Id say if you had four cats like the armada does, making test pipes for two of the cats would be ideal. Soooo, you have no signs of cats under your car?? I would at least try to find a cat that you can gut out to put under the car for visual. Even if your tubing is larger in diameter I dont think a smaller cat thats gutted out is gonna make much of a difference.

It is very simple and obvious of why a gutted cat will cause you to lose power, not too mention sound like crap. Best thing to do is have a offroad/test pipe made.
Why ruin a pretty expensive stock part when you can get 2 pipes with flanges made for cheap?

It is very simple and obvious of why a gutted cat will cause you to lose power, not too mention sound like crap. Best thing to do is have a offroad/test pipe made.
Why ruin a pretty expensive stock part when you can get 2 pipes with flanges made for cheap?
My muffler has plenty o backpressure. No placebo effect here. I felt the extra power. And oh yes, its because of visual that you want to keep the cats instead of 50 dollar test pipes with flanges. You got to just about beg to do for the illegal purposes for they know your gonna put it on a daily driver and not want the come back if something goes down. Inless you know sombody who welds on the side, no muffler shop in the world is gonna get involved with disconnecting cats,sizing up your flanges and inserting test pipes. Or are you just going to do the convience of removing the EM and handing it to them to weld for a few hps.?? There are no flanges on Armada pre cats after the em. If you do the main cats you may get an engine code, which in that case you can just remove the cats with ease and have them make you test pipes.

My muffler has plenty o backpressure. No placebo effect here. I felt the extra power. And oh yes, its because of visual that you want to keep the cats instead of 50 dollar test pipes with flanges. You got to just about beg to do for the illegal purposes for they know your gonna put it on a daily driver and not want the come back if something goes down. Inless you know sombody who welds on the side, no muffler shop in the world is gonna get involved with disconnecting cats,sizing up your flanges and inserting test pipes. Or are you just going to do the convience of removing the EM and handing it to them to weld for a few hps.?? There are no flanges on Armada pre cats after the em. If you do the main cats you may get an engine code, which in that case you can just remove the cats with ease and have them make you test pipes.


Back pressure? Usually when someone speaks of back pressure they are either subsituting it for the better/correct techical terms or just don't understand how an exhaust systems works.
It is exhaust velocity.....back pressure is bad.

With out dynos there is nothing but placebo. And I have seen many on the dyno try the cheap way of making more hp by gutting the cats have all turned out to be bad mistakes. Simple gutting them is definately not the smartest thing to do if you know anything about exhuast systems. You are breaking apart the internals of a cat! In doing so you are creating turbulence within the system....Not good. You would be better off welding a pipe inside of the cat after gutting it, but then again you are hurting performance buy closing the diameter of the piping.

There are test pipe made for alot of vehicles. And no you don't have to beg for a test pipe if you know how to ask for one. I have done it a few times before I picked up a welder or bought aftermarket made ones.
It is perfectly legal to have a test pipe made if it is not installed on the vehicle and the owner knows if is a off-raod use only part!
How do you think they are made in Cali of all places that have more aftermarket then any other place.

There are few ways yo get rid of the CEL from removal of the CATs.
And there are flanges on the cats to make a test pipe. If you want to remove the first cats get some headers.

there is a super easy and simple fix just fyi for those with gutted cats or testpipes to eliminate the triggering of the o2 sensor and the cel light.. it involves buying about 5$ in parts and the know how to use a drill.. if anyone wants more info let me know.. we use this all the time on the cars that still have the imability to re=program the ecu

and as turbo mz3 said .. its not about backpressure... its about velocity and scavenging of the gasses out of the motor.. this is done by actually using "tuned" pipes... this is the reason size and bends either more / less / crush type or mandrel makes such a difference... you are actually tuning the air flow of the system.. very similar to a pipe organ effect..the size and shape of the system actually increases or decreases the velocity of the air and the actual tuned freq of it resulting in either more or less air flow

Back pressure? Usually when someone speaks of back pressure they are either subsituting it for the better/correct techical terms or just don't understand how an exhaust systems works.
It is exhaust velocity.....back pressure is bad.

With out dynos there is nothing but placebo. And I have seen many on the dyno try the cheap way of making more hp by gutting the cats have all turned out to be bad mistakes. Simple gutting them is definately not the smartest thing to do if you know anything about exhuast systems. You are breaking apart the internals of a cat! In doing so you are creating turbulence within the system....Not good. You would be better off welding a pipe inside of the cat after gutting it, but then again you are hurting performance buy closing the diameter of the piping. All NA cars need some backpressure, even if its a little. Its not a turbo.

There are test pipe made for alot of vehicles. And no you don't have to beg for a test pipe if you know how to ask for one. I have done it a few times before I picked up a welder or bought aftermarket made ones.
It is perfectly legal to have a test pipe made if it is not installed on the vehicle and the owner knows if is a off-raod use only part!
How do you think they are made in Cali of all places that have more aftermarket then any other place.

There are few ways yo get rid of the CEL from removal of the CATs.
And there are flanges on the cats to make a test pipe. If you want to remove the first cats get some headers. Your loosing power? Look, in the REAL WORLD, guys who spin wrenches know what works, in the world of google you can tell you buddies all your internet experences. Your looking at nano with the gain, like a bend in a air induction pipe lol. Hone the sucker out and put the same size pipe if your that worried. Sorry to say, dynos differ and I will post my results when my next dyno day comes. Ive seen a few hps gains all the time. Sooo, how do you ASK for a test pipe?? Ohhh, I promise it will be for track, and dyno day only. Oh, why didnt you say so, step right up and I will make a bunch of them for you. Who cares if you get busted and the EPA comes knocking on my door not to bust me but to waste my time If i installed it on the ride or not, why I made it such and such. For you, no problem stranger!!!If you dont weld, you will need inside or muffler shop help. Like I said before,here is no flange on em side of the pre cat. You need to make flanges which will take some sweet wipping motion or a 250 dollar ew. Stillen sells a header that has flanges, jba doesnt. Stillen makes a emulator, jba doesnt. Soo, lmk how you would remove the mil light if it came on due to the cats on a ARMADA/Titan.

Your loosing power? Look, in the REAL WORLD, guys who spin wrenches know what works, in the world of google you can tell you buddies all your internet experences. Your looking at nano with the gain, like a bend in a air induction pipe lol. Hone the sucker out and put the same size pipe if your that worried. Sorry to say, dynos differ and I will post my results when my next dyno day comes. Ive seen a few hps gains all the time. Sooo, how do you ASK for a test pipe?? Ohhh, I promise it will be for track, and dyno day only. Oh, why didnt you say so, step right up and I will make a bunch of them for you. Who cares if you get busted and the EPA comes knocking on my door not to bust me but to waste my time If i installed it on the ride or not, why I made it such and such. For you, no problem stranger!!!If you dont weld, you will need inside or muffler shop help. Like I said before,here is no flange on em side of the pre cat. You need to make flanges which will take some sweet wipping motion or a 250 dollar ew. Stillen sells a header that has flanges, jba doesnt. Stillen makes a emulator, jba doesnt. Soo, lmk how you would remove the mil light if it came on due to the cats on a ARMADA/Titan.

In the real world you don't seem to have much experience here. Been there and done everything you stated. Just becuase you can't understand how things work doesn't mean your assumptions are right. Just because you haven't looked into anything doesn't mean it will be extremely expensive or even hard to do.

Some research might help your case alittle bit. But you seem to need alot more experience also. Stay away from google and get some real world experience and you should be fine.

And yes there are easy ways to get rid of CEL from removing the cats. If you have any electrical skills you could do it that way or you could use the anti-fouler trick.

there is a super easy and simple fix just fyi for those with gutted cats or testpipes to eliminate the triggering of the o2 sensor and the cel light.. it involves buying about 5$ in parts and the know how to use a drill.. if anyone wants more info let me know.. we use this all the time on the cars that still have the imability to re=program the ecu

and as turbo mz3 said .. its not about backpressure... its about velocity and scavenging of the gasses out of the motor.. this is done by actually using "tuned" pipes... this is the reason size and bends either more / less / crush type or mandrel makes such a difference... you are actually tuning the air flow of the system.. very similar to a pipe organ effect..the size and shape of the system actually increases or decreases the velocity of the air and the actual tuned freq of it resulting in either more or less air flow Please, lmk. I would like to know what 5 dollars and the skills of using a drill will acomplish.

In the real world you don't seem to have much experience here. Been there and done everything you stated. Just becuase you can't understand how things work doesn't mean your assumptions are right. Just because you haven't looked into anything doesn't mean it will be extremely expensive or even hard to do.

Some research might help your case alittle bit. But you seem to need alot more experience also. Stay away from google and get some real world experience and you should be fine.

And yes there are easy ways to get rid of CEL from removing the cats. If you have any electrical skills you could do it that way or you could use the anti-fouler trick. oh please, stop being a politician and just give us the info. I remember once how this guy told me how madrel bends in my ic tubing would increase power vs my welded crap. 3 hps for 4 hundred dollars. Ha, i remember how this google freak told me how open bovs give more power and rerouted ones loose power. This guy was boosting off like his mouth whilst my quit arse car was pulling.

oh please, stop being a politician and just give us the info. I remember once how this guy told me how madrel bends in my ic tubing would increase power vs my welded crap. 3 hps for 4 hundred dollars. Ha, i remember how this google freak told me how open bovs give more power and rerouted ones loose power. This guy was boosting off like his mouth whilst my quit arse car was pulling.


Those are nice stories, but have nothing to do with this topic! Not too mention half of it doesn't make sense at all!

There are many many articles on the internet on getting rid of the CEL from removing the cat. The simplest way is the anti-fouler that I stated and is what zfactor was mentioning. $5 in parts if that from the auto store and you should be good if you know how to "spin tools". Install one into the o2 bung, drill out the other for the o2 senser, install it and the o2 sensor on the 1st anti-fouler and you are done.
Some test pipes use a small j-pipe for the o2 sensor instead of the anti-foulers.

Those nonsense stories you added sound just like the one you are trying to pass here.....did some other guy tell you gutting a cat was good?

No,no, ive known if for years. Did somebody tell you that an anti fouler or whatever was good for cats? Why would they make a device to turn the mil off for removing cats?? Did they make the device for morons who remove cats for power gain? Your turn.

oh heres your prouct, would of never known of it either. http://www.autotube.net/index.html So whould you need four of them?? Two for the af meters and two for the downstream?? Depending on how many test pipes you want to put on?? 50 bucks per test pipe, flanges are an extra 20 bucks if you can find somebody to install, 50 bucks more four your device delvered for all four for an extra 5 hps. Thas almost 3 bills, man, you sound just like that guy who inspired me to get madrel bends for my ic for three measly hps for 4 bills.

Time to move on guys. This isn't going anywhere, and is not serving a useful purpose for CA.

No,no, ive known if for years. Did somebody tell you that an anti fouler or whatever was good for cats? Why would they make a device to turn the mil off for removing cats?? Did they make the device for morons who remove cats for power gain? Your turn.

I'll try to answer these questions, if you want the call them that, as civil as possible.

If you known for years then what are you asking for? An anti-fouler does just what you see it do, it moves the o2 sensor partly out of the exhaust flow.
They make a device to remove the CEL for the same reason there are headers and race pipes that remove factory cats......so you don't get a CEL! But just because that is out doesn't mean it is the only option available!
Not understanding that last question.
Not taking turns just hate to see bad information spread through an internet forum. It is just sad how much it takes to show someone they are wrong!


oh heres your prouct, would of never known of it either. http://www.autotube.net/index.html So whould you need four of them?? Two for the af meters and two for the downstream?? Depending on how many test pipes you want to put on?? 50 bucks per test pipe, flanges are an extra 20 bucks if you can find somebody to install, 50 bucks more four your device delvered for all four for an extra 5 hps. Thas almost 3 bills, man, you sound just like that guy who inspired me to get madrel bends for my ic for three measly hps for 4 bills.

Some vehicles use 1 some use 2 on a single o2 bung. I have used 2 and most race pipes with the j-pipe extenstion have been alot longer then 2 anti-foulers.
Anyway you add it up and as much as you pay for it, that is alot smarter and cheaper than destroying the stock cats. And not sure how you are getting $50 for the device(anti-foulers) when they are cheaper than $5. Even the parts to do it electrical is cheaper.

As for the IC bends they are the same as an exhaust. You need to have them properly made to the application, too big you might get lag, too small and you make the turbo work more. But I hope you are not trying to agree that crush bent is better than mandrel. Maybe you didn't fit the right size diamter piping or just went with his recommendations with out looking into it furter.


Time to move on guys. This isn't going anywhere, and is not serving a useful purpose for CA.

I appologize, just hard to let misinformation go.

Let me rewind back to the original question.
If you remove or gut out the cat, won't the o2 sensor detect that and lean out the fuel/air mixture?

Does the cat really have a noticeable effect on performance?

It seems like if it does lean out the mixture, it would actually slow you down and run hotter.

simple cat cel eliminator this will allow the o2 sensor to see only a very small flow of gasses simulating the same flow of the 02 sensor.. they do work i done this tonsssssss of times on lots of models of vehicles... less than 5$ to do this and the use of a good drill and vise..

http://i22.photobucket.com/albums/b313/zfactor2004/TXS004c.jpg

http://i22.photobucket.com/albums/b313/zfactor2004/Help003b.jpg

http://i22.photobucket.com/albums/b313/zfactor2004/Help001b.jpg

either of the 2 non foulers posted will work the same one is shorter than the other. the car will still "Think" the cat is there therefore no change in performance

Let me rewind back to the original question.
If you remove or gut out the cat, won't the o2 sensor detect that and lean out the fuel/air mixture?

Does the cat really have a noticeable effect on performance?

It seems like if it does lean out the mixture, it would actually slow you down and run hotter.
The 02 sensor doesn't have anything to do with the A/F ratio on the 5.6 engine. That is controlled by the A/F sensor. The A/F sensors are installed in the manifolds ahead of the first cats.
The O2 sensors are used to monitor emissions, not to control A/F ratios. They are installed in the mid pipes, between the primary and secondary cats.
On a stock or near stock engine removal of the cats won't help performance; it just puts you in violation of the law, makes more noise and causes more pollution.

On a stock or near stock engine removal of the cats won't help performance; it just puts you in violation of the law, makes more noise and causes more pollution.

I beg to differ here with the performance part. Having had a few cars on the dynos with race pipes installed there was a noticable difference in performance from stock to near stock.

And have seen some get through the sniffer without any cats.

Performance wise one of the best things you can do is open up the intake and exhaust by removing all restrictions...cats!

I have also had a car that removing the cats gained alittle bit on the dyno but sounded like ***.

I definately wont do it on the aramda but on a few cars where making the most whp/wtq I could make on that setup the cats were gone.

oh man, this is starting to sound like the time I asked if anybody had a smaller belt to bypass the ac compresser for cold weather dayz. I got attacked left and right. You ppl are full of it. I will lay down results next month.

I'll try to answer these questions, if you want the call them that, as civil as possible.

If you known for years then what are you asking for? An anti-fouler does just what you see it do, it moves the o2 sensor partly out of the exhaust flow.
They make a device to remove the CEL for the same reason there are headers and race pipes that remove factory cats......so you don't get a CEL! But just because that is out doesn't mean it is the only option available!
Not understanding that last question.
Not taking turns just hate to see bad information spread through an internet forum. It is just sad how much it takes to show someone they are wrong!




Some vehicles use 1 some use 2 on a single o2 bung. I have used 2 and most race pipes with the j-pipe extenstion have been alot longer then 2 anti-foulers.
Anyway you add it up and as much as you pay for it, that is alot smarter and cheaper than destroying the stock cats. And not sure how you are getting $50 for the device(anti-foulers) when they are cheaper than $5. Even the parts to do it electrical is cheaper.

As for the IC bends they are the same as an exhaust. You need to have them properly made to the application, too big you might get lag, too small and you make the turbo work more. But I hope you are not trying to agree that crush bent is better than mandrel. Maybe you didn't fit the right size diamter piping or just went with his recommendations with out looking into it furter.




I appologize, just hard to let misinformation go. Bro, your worse than a politican, at least they get to the point sooner or later. Restriction is restriction. I know gutting out cats give power. I dont care what you or mr. never been to a tack with his armada sez...They offer it for ten bucks on the page i showed. Shipping may or not be gratis. 4x9.99=

Since you guys can't seem to take a hint I will now close this thread. Any more mouthing back and forth like this will result in a lot more than a thread closing.