When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Are those actually cats or are they just resonators?
I call anything past the O2 sensor a resonator. With resonators that are near the exhaust tips, I use the word muffler. But in reality they are very similar in construction. They are there mostly to kill noise, not capture pollutants.
Are those actually cats or are they just resonators?
I call anything past the O2 sensor a resonator. With resonators that are near the exhaust tips, I use the word muffler. But in reality they are very similar in construction. They are there mostly to kill noise, not capture pollutants.
resonators is what they are, no sensors or anything, right after the cats on the LT4.
I did the same thing, Bought X Pipe from Borla and then the Atak system around 2 grand
And was disappointed . What a shame took them off put stocks back on and much happier.
Very disappointed with the Borla Atak set up
Sounded better but what a waist. Very disappointed with wasting money for bad results
Was looking at getting a x pipe and new mufflers. But the OEM x pipe flows good enough. the only reason i see the need for one is to remove the secondaries. Just to complement the after market mufflers. (sound)
I would rather save the money and just cut and weld pipe where the cats once where. I nor does anyone on the street care about what my car looks like underneath. So putting that aside.
It doesn't look like much room to cut on the one side. Can this be done ?
Have thought the same thing! The OEM pipes with NPP are large and Vettes' have had crossovers for years.! The approach shown in the pic below would be even easier! If you had a small welder could do it as a DIY. Cut a large section from the topside of the CATS with a cut-off wheel (so inspection would not see it) then remove the internals and weld the cut top section back! Might even be able to sell the platinum etc to a scrape yard!!
OEM Pipes and crossover are better than some of the kits!
Are those actually cats or are they just resonators?
I call anything past the O2 sensor a resonator. With resonators that are near the exhaust tips, I use the word muffler. But in reality they are very similar in construction. They are there mostly to kill noise, not capture pollutants.
Originally Posted by mark mc williams
resonators is what they are, no sensors or anything, right after the cats on the LT4.
Regardless of what you think they are or what you call them, they are indeed catalytic converters. Their purpose is not noise related but rather emissions reduction to meet the current government standards.
Regardless of what you think they are or what you call them, they are indeed catalytic converters. Their purpose is not noise related but rather emissions reduction to meet the current government standards.
car is way louder with the secondary Cats.resonators removed, it was quite with them on the car, put on the Borla Attack mufflers with NPP first, didnt notice much of a differance in sound, then added on the Borla 60547 X pipe that eliminated the factory X pipe, and car is way louder. the dealer called them Resonators, some call them Cats, Either way, car lost torq with the new X pipe and mufflers.
Last edited by mark mc williams; 02-14-2018 at 01:18 PM.
car is way louder with the secondary Cats.resonators removed, it was quite with them on the car, put on the Borla Attack mufflers with NPP first, didnt notice much of a differance in sound, then added on the Borla 60547 X pipe that eliminated the factory X pipe, and car is way louder. the dealer called them Resonators, some call them Cats, Either way, car lost torq with the new X pipe and mufflers.
More than not am sure it did lose some power on a stock set up & motor. But cam the car & are blower set up & you will make more power with the borla x pipe on the car...Robert
More than not am sure it did lose some power on a stock set up & motor. But cam the car & are blower set up & you will make more power with the borla x pipe on the car...Robert
i dint want to loose my factory warranty , cant re tune it,, but i will put my factory X pipe back on.
i dint want to loose my factory warranty , cant re tune it,, but i will put my factory X pipe back on.
I would agree with that. If you are unwilling to tune the car, then you(everyone) should leave the car completely stock except for an axle back exhaust.
The cars today are very sensitive to any changes. Removing secondary cats or even gutting them requires tuning the ECU to return the low end torque.
I would agree with that. If you are unwilling to tune the car, then you(everyone) should leave the car completely stock except for an axle back exhaust.
The cars today are very sensitive to any changes. Removing secondary cats or even gutting them requires tuning the ECU to return the low end torque.
Yes, also Borla needs to re evaluate there X pipe and mufflers for the New C7 z06's and mention Re Tune will be needed, or you loose bottom end TorQ. Borla told Me They dyno tested the pipes in 2015 only. very disapointed with loss of bottom end Torq now.on my 2017 C7 Z06.
Have thought the same thing! The OEM pipes with NPP are large and Vettes' have had crossovers for years.! The approach shown in the pic below would be even easier! If you had a small welder could do it as a DIY. Cut a large section from the topside of the CATS with a cut-off wheel (so inspection would not see it) then remove the internals and weld the cut top section back! Might even be able to sell the platinum etc to a scrape yard!!
OEM Pipes and crossover are better than some of the kits!
If I was going to do the above modification I would insert & tackweld in a piece of tubing of the proper dimensions for a smoother flow through the empty cats. Due to the exhaust 'not' really escaping to the outside atmosphere I don't think it would be a 'big deal' if the tubing is tacked in place.
PS: I think the factory X-pipe is about as good as an X-pipe can get.
Last edited by C7/Z06 Man; 02-14-2018 at 10:00 PM.
Regardless of what you think they are or what you call them, they are indeed catalytic converters. Their purpose is not noise related but rather emissions reduction to meet the current government standards.
There is no emissions checking device after the O2 Sensors.
So how is it keeping emissions compliance? The PCM/ECM needs to be aware of anything emissions related. This requires a closed-looped system.
Those devices are not within the closed loop, therefore they cannot LEGALLY be part of the emissions system.
If I was going to do the above modification I would insert & tackweld in a piece of tubing of the proper dimensions for a smoother flow through the empty cats. Due to the exhaust 'not' really escaping to the outside atmosphere I don't think if would be a 'big deal' if the tubing is tacked in place.
PS: I think the factory X-pipe is about as good as an X-pipe can get.
That's exactly what I was thinking. Once cleared out, the big cavernous section can't be helpful. Weld in a section of tubing.
Yes, also Borla needs to re evaluate there X pipe and mufflers for the New C7 z06's and mention Re Tune will be needed, or you loose bottom end TorQ. Borla told Me They dyno tested the pipes in 2015 only. very disapointed with loss of bottom end Torq now.on my 2017 C7 Z06.
If you mean their X pipe that deletes the secondary cats then yes, the reason is the knock retard that is seen after secondary cat removal.
If you get the Xpipe that retains the secondary cats then there is zero issue and you do not lose low end torque.
Question: A stock C7 Grand Sport, if you add only Borla X-Pipe, remove secondary cats, What do you get besides a little louder/throatie/aggressive sound? Do you also loose low end torq?
If you have an AFE and are just adding Borla X-Pipe and moving secondary cats, should you just leave it stock x-pipe?
Care to provide proof? Based on what I know about emissions and FMVSS I don't see anything that agrees with you.
You've provided nothing to prove your point just telling us we are wrong. As the person making the DEFINITIVE claim, it is up to you to show proof.
Being that I said it's not a part of the closed look system (if it is, please explain how), and that legally the ECM/PCM has to know about all emissions (if it doesn't how can a simple OBD read pass an emissions test?) So far, nothing I've said is incorrect other than the argument over if it is a cat. I ask again (for a third time in this post). PROVE IT.
Care to provide proof? Based on what I know about emissions and FMVSS I don't see anything that agrees with you.
You've provided nothing to prove your point just telling us we are wrong. As the person making the DEFINITIVE claim, it is up to you to show proof.
Being that I said it's not a part of the closed look system (if it is, please explain how), and that legally the ECM/PCM has to know about all emissions (if it doesn't how can a simple OBD read pass an emissions test?) So far, nothing I've said is incorrect other than the argument over if it is a cat. I ask again (for a third time in this post). PROVE IT.
Where is your proof to say I am wrong? How about you prove it. In 2012 GM added secondary cats to meet EPA regulations demanded by the US government. This obviously caused them an increased cost in production as cats are expensive. Do you think they just did it for fun? If a secondary cat fails, GM is responsible for fixing it under the 100,000 mile emissions warranty. Not sure why you think you're assumption is right. I'm so confident that I have no care or need to provide you proof. Continue thinking what you will. IDGAF
Last edited by Internets_Ninja; 02-15-2018 at 05:20 PM.
Question: A stock C7 Grand Sport, if you add only Borla X-Pipe, remove secondary cats, What do you get besides a little louder/throatie/aggressive sound? Do you also loose low end torq?
If you have an AFE and are just adding Borla X-Pipe and moving secondary cats, should you just leave it stock x-pipe?
If you get the Borla X pipe that deletes the secondary cats you will get a louder exhaust. There have been issues with secondary cat deletes where the ECU picks up more/false knock retard making it feel like you lose low end torque. It's not that you actually lose low end torque, its that the knock retard shows up in the low end area and pulls timing which gives the feeling of lost power. I mean it really is lost power I suppose because of the reduced timing, but if this is negated via a tune then you will have no lost power. You probably wont have any gained power either if you only tune to correct the false knock.
If you add an AFE intake you will pick up some power due to the air fuel ratio leaning out. However, untuned you can lose efficiency and your MPG can drop a little. Also the AFE has no affect on the false knock from the secondary cat delete. So you will still run into this issue. But if you do both mods at the same time if may be less noticeable.
Which brings me back to the point that unless you plan to tune your car, I subjectively feel like any mods is a waste of time. Adding an AFE intake without a tune may get you a little bit of power but not enough to feel a difference. The car is going to change its long term fuel trims and eventually the gains are maybe 10hp, and fuel mileage will drop a little. If you do xpipe, catback, and AFE WITH a tune, you could potentially pick up 20 rwhp. If you want to keep MPG and drive ability like stock and you are willign to tune your ECU, I would recommend an Intake like AFE, a ported throttle body, ported intake manifold, Borla Xpipe with 2nd cat delete, and(optional) borla/cosra axle back. Anything short of this and you cannot feel the additional power regardless of what the forums say. (With exception to Z06's and aftermarket intakes. This is enough of a gain that you can feel)
Where is your proof to say I am wrong? How about you prove it. In 2012 GM added secondary cats to meet EPA regulations demanded by the US government. This obviously caused them an increased cost in production as cats are expensive. Do you think they just did it for fun? If a secondary cat fails, GM is responsible for fixing it under the 100,000 mile emissions warranty. The secondary cats do not trigger a CEL but it is still monitored by the ECU. Not sure why you think you're assumption is right. I'm so confident that I have no care or need to provide you proof. Continue thinking what you will. IDGAF
Um, I don't think you understand how ECU's work. This is why I'm so confident I'm right.
To monitor the exhaust, you'd have to have a sensor. Where is the sensor? If no MIL (that's the correct name BTW for the lamp in your cluster) is thrown then how do you know there is an error?
You're trying to brush me off because clearly you lack the technical knowledge and the ability to articulate your point with facts. I'm stating facts.
Emissions testing is done thru the monitoring of various sensors in the intake and exhaust systems. These sensors allow a closed loop monitoring function to operate (I don't think you understand controls, let along know what a closed loop system is at this point). When a monitoring function detects a problem it throws a DTC (that's a diagnostic Trouble Code) and raises the MIL light to notify the driver. If there are no DTCs and there is no MIL light there is no problem.
An emissions control device that has no sensor, no monitor, and no DTC/MIL notification is not a control device. That's engineering, something you clearly do not understand.
And I do give a ****, because I'm sick and tired of people who are ignorant spreading DISINFORMATION on the internet. You sir are a piece of work, swoop in, challenge my statements which I have backed up with sound logic and engineering knowledge and then claim you don't need to prove yourself. In the future what you should do is refrain from speaking.
02-13-2018, 07:56 PM
Robert
