Dual Mode (NPP) Exhaust Issue

[RonnieG]

Was wondering if anyone else has had issue with their NPP exhaust.. the valves wont open like they're supposed to after revving past 3,500.. i'm still in the break in period and the highest I've revved is near 5,000rpm and nothing.. once I hit 1,500 ill try getting it near 6,000.. They're open at idle and when the car is off but afterwards stay closed..

I've searched and couldn't find anyone with this issue on a Camaro but I have seen one other person experiencing this on a vette..

i'm going to have it checked out on Saturday but I was hoping that maybe someone might have some info.. if possible I would love to fix it myself or outside a dealership as my past experiences with dealerships lead me to believe that they suck and don't care for the most part and I don't trust them at all. twice ive been to a dealership where the employee would toy with my car.. maybe they expected me to sit at the desk while they go out and drive it, but my Camaro is my baby and I always watch how they handle it as much as I can.

I bought my Camaro on May 25 and I've 1,450 miles on it.

[Phidelt59]

I haven't had any issues on mine. I have about 3,300 miles on it now and it still sounds great throughout the rev range. The only issue I am having is with the hurst shifter I got factory installed. It gets real notchy between 1st and 2nd gear when it's cold after the car has been sitting for several hours.

[Tara Martin]

I've never had a problem with my NPP, but I pulled the fuse anyway and it's open all the time now. Frankly, I didn't notice much of a change. Especially at speed, I don't notice a change in volume. I guess someone outside or following me might notice a difference...

Tara

[GAHDOOSH]

My research suggests that after 3,500 RPM they are supposed to close, silencing any rasp that may come out. If this is the issue you are having, there is an easy fix. Below is a link with details on how to remove the fuse that closes those flaps at higher RPM's. It takes about five minutes and I think you'll like the difference.

http://www.camaro5.com/forums/showthread.php?t=268970

[DuskSS]

Originally Posted by RonnieG

Was wondering if anyone else has had issue with their NPP exhaust.. the valves wont open like they're supposed to after revving past 3,500.. i'm still in the break in period and the highest I've revved is near 5,000rpm and nothing.. once I hit 1,500 ill try getting it near 6,000.. They're open at idle and when the car is off but afterwards stay closed..

I've searched and couldn't find anyone with this issue on a Camaro but I have seen one other person experiencing this on a vette..

i'm going to have it checked out on Saturday but I was hoping that maybe someone might have some info.. if possible I would love to fix it myself or outside a dealership as my past experiences with dealerships lead me to believe that they suck and don't care for the most part and I don't trust them at all. twice ive been to a dealership where the employee would toy with my car.. maybe they expected me to sit at the desk while they go out and drive it, but my Camaro is my baby and I always watch how they handle it as much as I can.

I bought my Camaro on May 25 and I've 1,450 miles on it.

The Camaro setup is different than the vette. it should be closing around 2k and staying closed to well over 3k only opening when you get close to 4K+
To test you should pull the fuse and see if you are just expecting too radical of a note change.

Stock with my DM on I could barely tell at all when it opened up at 4K.

Now that it is modded it is MUCH bigger of a difference.

I'm betting it is working and you are expecting more volume than the stock headers and cats will allow.

also have someone else sit in the car with you behind it.. hold it in the 2-3k range then gradually move it out with you behind. I'm betting you will hear it.

Inside the car the 13 has AMAZING noise insulation and even with an exhaust that will deafen people directly behind me with the DM on and the windows up no stereo or AC on the car is super quiet inside. but behind is loud as hell.

[DuskSS]

Originally Posted by GAHDOOSH

My research suggests that after 3,500 RPM they are supposed to close, silencing any rasp that may come out. If this is the issue you are having, there is an easy fix. Below is a link with details on how to remove the fuse that closes those flaps at higher RPM's. It takes about five minutes and I think you'll like the difference.

http://www.camaro5.com/forums/showthread.php?t=268970

actually the DM on the camaro closes at around 2k and opens back up at that RPM.
it has a much different function than the Corvette version.

you can easily hear this on a modded car much easier you can literally hear the valves close and open.

[RonnieG]

Originally Posted by Phidelt59

I haven't had any issues on mine. I have about 3,300 miles on it now and it still sounds great throughout the rev range. The only issue I am having is with the hurst shifter I got factory installed. It gets real notchy between 1st and 2nd gear when it's cold after the car has been sitting for several hours.

it's been warm down here in florida but I've also ran into the nochy issues.. on my v6 it went away after around 6,000 miles.. with me the nochiness seems to happen more frequently after its been sitting for a while.. it doesn't want to go into first or reverse smoothly.. i'm hoping it will disappear after some time

Originally Posted by Tara Martin

I've never had a problem with my NPP, but I pulled the fuse anyway and it's open all the time now. Frankly, I didn't notice much of a change. Especially at speed, I don't notice a change in volume. I guess someone outside or following me might notice a difference...
Tara

hmm.. this might make me try it out then.. from what other have posted I thought not to since it seemed like it would be crazy loud.

Originally Posted by GAHDOOSH

My research suggests that after 3,500 RPM they are supposed to close, silencing any rasp that may come out. If this is the issue you are having, there is an easy fix. Below is a link with details on how to remove the fuse that closes those flaps at higher RPM's. It takes about five minutes and I think you'll like the difference.

http://www.camaro5.com/forums/showthread.php?t=268970

thanks for the link!

Originally Posted by DuskSS

The Camaro setup is different than the vette. it should be closing around 2k and staying closed to well over 3k only opening when you get close to 4K+
To test you should pull the fuse and see if you are just expecting too radical of a note change.
Stock with my DM on I could barely tell at all when it opened up at 4K.
Now that it is modded it is MUCH bigger of a difference.
I'm betting it is working and you are expecting more volume than the stock headers and cats will allow.
also have someone else sit in the car with you behind it.. hold it in the 2-3k range then gradually move it out with you behind. I'm betting you will hear it.
Inside the car the 13 has AMAZING noise insulation and even with an exhaust that will deafen people directly behind me with the DM on and the windows up no stereo or AC on the car is super quiet inside. but behind is loud as hell.

Judging from youtube videos, my v6 with dual mode, and revving it high on the road and in idle, i'm led to believe there's a problem with it.. if it is working normally i'm super disappointed and buying the borla atak.. but as a betting man, i'd put money down that its not functioning as it should... I was super satisfied with this exhaust on the v6 but the sound change just isn't there with this one..
anywho, I will be pulling the fuse before I bring it to the dealership to check, however I will need it to close and fix the issue since i'm moving to NY and the cops are ticket happy when it comes to loud exhaust.

[Chevrolet Customer Svc]

Originally Posted by RonnieG

Was wondering if anyone else has had issue with their NPP exhaust.. the valves wont open like they're supposed to after revving past 3,500.. i'm still in the break in period and the highest I've revved is near 5,000rpm and nothing.. once I hit 1,500 ill try getting it near 6,000.. They're open at idle and when the car is off but afterwards stay closed..

I've searched and couldn't find anyone with this issue on a Camaro but I have seen one other person experiencing this on a vette..

i'm going to have it checked out on Saturday but I was hoping that maybe someone might have some info.. if possible I would love to fix it myself or outside a dealership as my past experiences with dealerships lead me to believe that they suck and don't care for the most part and I don't trust them at all. twice ive been to a dealership where the employee would toy with my car.. maybe they expected me to sit at the desk while they go out and drive it, but my Camaro is my baby and I always watch how they handle it as much as I can.

I bought my Camaro on May 25 and I've 1,450 miles on it.

RonnieG,

Truly sorry to hear about the exhaust. Please keep us updated on the diagnosis at the dealer on Saturday. Appreciate it!

William R.
Chevrolet Customer Care

[Chevrolet Customer Svc]

Originally Posted by Phidelt59

I haven't had any issues on mine. I have about 3,300 miles on it now and it still sounds great throughout the rev range. The only issue I am having is with the hurst shifter I got factory installed. It gets real notchy between 1st and 2nd gear when it's cold after the car has been sitting for several hours.

Phidelt59,

Same courtesy extends to you if a dealer visit is in the works to have this addressed. Let us know how the car continues to operate!

William R.
Chevrolet Customer Care

[cottrellj2]

Pulling the fuse on a NPP just makes it sound like a regular aftermarket exhaust IMO. You hear it all the time, but softly. You may notice more burbling or popping when you coast to a stop. I like it myself.

[DuskSS]

Originally Posted by RonnieG

it's been warm down here in florida but I've also ran into the nochy issues.. on my v6 it went away after around 6,000 miles.. with me the nochiness seems to happen more frequently after its been sitting for a while.. it doesn't want to go into first or reverse smoothly.. i'm hoping it will disappear after some time



hmm.. this might make me try it out then.. from what other have posted I thought not to since it seemed like it would be crazy loud.



thanks for the link!



Judging from youtube videos, my v6 with dual mode, and revving it high on the road and in idle, i'm led to believe there's a problem with it.. if it is working normally i'm super disappointed and buying the borla atak.. but as a betting man, i'd put money down that its not functioning as it should... I was super satisfied with this exhaust on the v6 but the sound change just isn't there with this one..
anywho, I will be pulling the fuse before I bring it to the dealership to check, however I will need it to close and fix the issue since i'm moving to NY and the cops are ticket happy when it comes to loud exhaust.

V6 cant compare to the V8 version at all not even close.
the V8 is much more smooth sounding..
but I sure as hell would not trade it for Borla..

I did pull the fuse day 1 as it was not that much a difference stock. mainly becasue you cannot hear it in the car due to how well the car is insulated.
others especially with stock old style complement it stock.. and like I said you really have to be behind the car to truely appreciate how loud the NPP is and how it changes.
but once you go LT headers.. holy crap does the DM/NPP come alive and become truly useful and EVIL sounding.
People stop my all the time and ask what exhaust I have now and never believe me when I tell them it is stock.

[Phidelt59]

Originally Posted by Chevrolet Customer Svc

Phidelt59,

Same courtesy extends to you if a dealer visit is in the works to have this addressed. Let us know how the car continues to operate!

William R.
Chevrolet Customer Care

I am taking the car in on Monday morning for the notchy shifting. I also just developed a rattle/squeaking noise from the passenger side when I go over bumps. I will update and let you know what they find.

[Chevrolet Customer Svc]

Originally Posted by Phidelt59

I am taking the car in on Monday morning for the notchy shifting. I also just developed a rattle/squeaking noise from the passenger side when I go over bumps. I will update and let you know what they find.

Appreciate the response Phidelt59,

Definitely sorry to hear about the concerns. Please keep me updated and don't hesitate to send me a PM with what happens at the dealership.

William R.
Chevrolet Customer Care