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the valves in the exhaust are retained when one changes the axle back i believe, and they can still be activated to various modes when using an aftermarket exhaust, like bullets or prt s and corsa . would this be a good assumption ?
the valves in the exhaust are retained when one changes the axle back i believe, and they can still be activated to various modes when using an aftermarket exhaust, like bullets or prt s and corsa . would this be a good assumption ?
tia.
Axle back will eliminate the factory valves (NPP). You can get after market.
Every axle back exhaust is different-----Some delete the AFM butterfly valves--some don't
If you purchase a system that deletes those butterflies----and unplug the pigtails you will get a DTC----and will have to have a tuner delete the AFM butterfly codes permanently so they will not re appear--------I have found that best just to leave those AFM butterflies in place---There is almost NO HP loss to simply turning off the AFM and leaving those valves simply open all the time---
I kind of wanted to change the axle back but retain the valves and still be able to choose a setting, and have growl, but that can t happen then i see.
Akrapovic and others make axle-backs that still have the NPP valves. But some don't.
So in short, if you want to keep the exhaust adjustability AND have a cat-back, you need to buy one that has the valves in it. You will likely retain and use the stock activators (motors) but the valves have to be there, you can't fake it or use your old ones.
Here's someone else's picture of an aftermarket cat-back that does have the valve, which I circled.
Thanks Dave, maybe I'll just go with a cat delete mid pipe and see how that works, I need to be able to rattle the windows in the hood. Lol. And retain my warranty for a bit. I can t have it both ways i see.
Last edited by walleyejack; Dec 26, 2016 at 08:38 PM.
Thanks Dave, maybe I'll just go with a cat delete mid pipe and see how that works, I need to be able to rattle the windows in the hood. Lol. And retain my warranty for a bit. I can t have it both ways i see.
That would be my recommendation. The NPP axlebacks aren't causing the "too quiet" condition. It's all the junk between the NPP axlebacks and the engine (i.e. exhaust manifolds, stock cats, stock midpipe).
That would be my recommendation. The NPP axlebacks aren't causing the "too quiet" condition. It's all the junk between the NPP axlebacks and the engine (i.e. exhaust manifolds, stock cats, stock midpipe).
Thanks for your input.
I did talk to a supporting vendor and he said midpipe would do virtually nothing for the tone with npp.
Gotta think about spending 500 bones on this or going with Fusions.
I did talk to a supporting vendor and he said midpipe would do virtually nothing for the tone with npp.
Gotta think about spending 500 bones on this or going with Fusions.
The stock midpipe has the resonators/secondary cats built into them which do contribute to some muffling...
I suppose it depends on what you're after. Mine was just too quiet so I installed Kooks 1 7/8" LTs + Kooks green cats + Kooks midpipe and am running the stock NPP mufflers. The tone isn't much different from stock but the volume (decibels) is greatly increased which was what I was after. It does have a higher pitch tone to it at the upper RPM range though.
The stock midpipe has the resonators/secondary cats built into them which do contribute to some muffling...
I suppose it depends on what you're after. Mine was just too quiet so I installed Kooks 1 7/8" LTs + Kooks green cats + Kooks midpipe and am running the stock NPP mufflers. The tone isn't much different from stock but the volume (decibels) is greatly increased which was what I was after. It does have a higher pitch tone to it at the upper RPM range though.
Headers was my mission, but with only 4500 miles i don t want jeprodize the engine warranty yet. 😣
Headers was my mission, but with only 4500 miles i don t want jeprodize the engine warranty yet. 😣
LOL - You have more miles on yours than I do...I just turned 4,000 before putting her in hibernation. With that said, I feel your concern about the warranty which is why I went with the Kooks LTs + Kooks green cats because they are supposed to not throw a CEL on an untuned car. So far that has held true for my situation. I have not tuned my car and have no plans of doing so in order to help protect against any warranty issues.
[QUOTE=lakemg;1593774666]LOL - You have more miles on yours than I do...I just turned 4,000 before putting her in hibernation. With that said, I feel your concern about the warranty which is why I went with the Kooks LTs + Kooks green cats because they are supposed to not throw a CEL on an untuned car. So far that has held true for my situation. I have not tuned my car and have no plans of doing so in order to help protect against any warranty issues.[/QUOTE
That sounds good, how many miles since u put them on ? and did not require a tune, i guess not, to get max out of it anyway. never come across that thread or info. definately looking into it.
but it still could be problem with warranty if there is an engine faliure and GM says no...
Last edited by walleyejack; Jan 1, 2017 at 07:07 PM.
LOL - You have more miles on yours than I do...I just turned 4,000 before putting her in hibernation. With that said, I feel your concern about the warranty which is why I went with the Kooks LTs + Kooks green cats because they are supposed to not throw a CEL on an untuned car. So far that has held true for my situation. I have not tuned my car and have no plans of doing so in order to help protect against any warranty issues.[/QUOTE
That sounds good, how many miles since u put them on ? and did not require a tune, i guess not, to get max out of it anyway. never come across that thread or info. definately looking into it.
but it still could be problem with warranty if there is an engine faliure and GM says no...
I ran them about a month or so prior to putting it in hibernation so probably about 500 miles or so.
You're right...there's always the chance with the warranty piece if GM says so, but I was willing to take a "limited" chance knowing that if I tuned it and had issues, the warranty would be more likely to be rejected than not tuned.
I installed the system myself and can help with any questions you might have about it end up looking more into it. Here's a short video that I did of mine to give you a feel for what it sounds like. If you fast forward to around 4:00 I get into the throttle a bit more, but it's so loud, it maxes out the microphone's range.
They are definitely more $$$, but I wanted the green cats for the peace of mind of having no CEL issues. With that said, I later learned that one of my local Corvette friends installed the stainless works headers without cats on his C6 LS3 and he is not getting a CEL.
So it's very possible that I could have accomplished a no CEL situation with Kooks standard (non-green) highflow cats but would have been more of a gamble in my mind.
I ran them about a month or so prior to putting it in hibernation so probably about 500 miles or so.
You're right...there's always the chance with the warranty piece if GM says so, but I was willing to take a "limited" chance knowing that if I tuned it and had issues, the warranty would be more likely to be rejected than not tuned.
I installed the system myself and can help with any questions you might have about it end up looking more into it. Here's a short video that I did of mine to give you a feel for what it sounds like. If you fast forward to around 4:00 I get into the throttle a bit more, but it's so loud, it maxes out the microphone's range.
They are definitely more $$$, but I wanted the green cats for the peace of mind of having no CEL issues. With that said, I later learned that one of my local Corvette friends installed the stainless works headers without cats on his C6 LS3 and he is not getting a CEL.
So it's very possible that I could have accomplished a no CEL situation with Kooks standard (non-green) highflow cats but would have been more of a gamble in my mind.
two different engine setups tho. i had a c6 and headers and no cats also. and no check engine light. i don t want to get codes and have to delete them, like you, and then have a claim denied due to erasing codes, as Gm can see what has been going on.
Couldn't find a definative answer
