bigdaddyj25

Installed bullets on my c7 yesterday and drove it home about 65 miles no problems. Got in today and fired her up went to a couple stores and at my last stop before heading home my engine light came on. One note for those that might can help I took the NPP exhaust off my car to install the bullets. Supposedly this system was to be installed without throwing codes. I really don't know what to do at this point any help would be great. Thanks.

owc6

I have a set on order, waiting to be delivered/installed, so this is also a question I'm interested in.

Hopefully, this is not an actual issue, but just a loose "something" on this install.

Matt26

Check out this thread:

http://forums.corvetteforum.com/c7-t...ck-result.html

You removed the actuators so it thinks the system is broken.

You might try changing the engine sound management to the other setting

Jack Be Quick Racing

Between the NPP and Billy Boats - how is the sound around town and highway?

Hopefully you get the thrown code resolved.

EVL-C8

Do the codes only happen with the NPP cars? I have a BB system on the way to put on my NON-NPP Stingray ..... Hopefully it's different? Sounds like a PITA for just a bolt on mod!

Motohead279

You should not have any issues.

bigdaddyj25

The sound to me is amazing! The NPP sounds good but the bullets are much deeper and more aggressive. Again I guess it really just depends on what you are looking for.

bigdaddyj25

So is it going to hurt to drive it until I can figure out how to clear the code? Any other suggestions as to how to clear? The engine sound management is set to off already.

B Stead

I would put the BB Fusion on a NPP C7.

But if the code is not some kind of lean combustion situation then it must be because of not having the NPP wires connected to something. So resistors on the wires might work
.

bigdaddyj25

You would do the fusion even if you wanted the wide open sound all the time? Just curious.

Theta

I didn't see this had a dedicated thread until you posted in the NPP fuse thread.

If you'd like me to help you over here, that works, as well. Just need to know the answers to the questions posted over there.

Motohead279

I would imagine the code is not a big issue. Only way to know what the code is/clear the code is to go to the dealer, auto parts store, or buy a scanner.

Theta

I also asked him to get the code from OnStar (about the only perk of that other than Emergency Services) and I would look into it tonight.

If he physically removed the rear actuators, it will be a CCM group code. I have a P-list sitting here waiting for the code result.

But the code is minor, and shouldn't hurt a thing - it's simply alerting you to a problem that's (literally) not there.

2vetteEd

I have a set of Billy Boat Fusion with Bi Modul control on order, and this will be installed by my speed shop, Redline Motorsports. I assume from what I've been told, these exhaust system will work in conjunction with the driver mode software that's already in place for the NPP factory exhaust.

I certainly hope this is the case since the last thing I need is the thing chucking engine check lights at me!

I'm also getting American Racing headers, 1 7/8", and the X pipe. Along with the Green air filter already installed, this should be a cool setup.

bigdaddyj25

Ok so according to on star the code is P26C8.

Theta

P26C8 = NPP Valve Stuck / Non-Operational

Alright, now that we know that... Did you remove the NPP rear actuators (if you have a non-bimodal B&B system)?

B Stead

I would not get NPP and then disable the AFM. And then remove the AFM valves from the engine and put on an aftermarket exhaust system of my choice. (The Flowmaster doesn't have any muffler valves and I wonder who else is going to do that.)

Now there is tuning to disable the AFM but I haven't heard of any tuning to disable the NPP. I wonder if disabling the AFM would fix the problem here because when the AFM turns on that turns off the NPP.

Another idea, put some NPP muffler valves in the trunk and run the wires to them.


I assume that the BB Bullet muffler is not popping ?
.

Theta

Not entirely. When AFM kicks in, it is actually supplying a +12v signal to the NPP to keep the valves closed. So, disabling AFM will not affect the NPP in this specific case.

This isn't too far off from what may need to be done if the signal is PWM (which I believe it is). Instead of a 'clunky' solution, though, we may be able to replicate the PWM or simply remove the computer/electrical portion of the valve and encase it in a weatherproofed material and tie it back up into the harness.

Theta

Of course - when AFM kicks in, the goal of the system is to keep the system as quiet as possible.

The NPP valves close in order for the exhaust to travel through the muffled/baffled (middle) tailpipes only.

B Stead

Well, does the AFM operation check to see if the NPP valves are in the correct position or check to see if they are working ?

NPP working or not working doesn't really matter except in four-cylinder mode
.