[Lithias]

Updating from my morning drive. Squeak was barely audible, I did notice significant buildup in the exhaust pipe and on the valves themselves, like pitch black, so I'll be spraying them down tonight and giving them a good clean as safely as possible.

The squeak is only when the valve closes and does not squeak when opening, completely the opposite of my original problem with the first exhaust.

I could not hear anything with the windows down and driving, however it was audible when parked, but not any worse than with the windows up.

Will clean tonight and update again.

[cskipgo]

Sorry to hear this, dealing with the same thing here.

I also hear mine constantly in California traffic as it is transitioning from V8 to V4.

[Lithias]

Originally Posted by cskipgo

Sorry to hear this, dealing with the same thing here.

I also hear mine constantly in California traffic as it is transitioning from V8 to V4.

This is the AFM actuators, which I've heard is worse. Mine does not squeak on the v4 to v8 swap or vice versa.

I would find a dealer willing to work with you. Just be upfront, show them the forum postings and what was done. My dealer didn't hesitate with the original exhaust, they performed the recommend service twice and when it failed the third time, they contacted GM to authorize the exhaust replacement.

[Cechk01]

Any reason you dont want to just pull the NPP fuse? It will be loud all the time.

[Lithias]

Originally Posted by Cechk01

Any reason you dont want to just pull the NPP fuse? It will be loud all the time.

I paid for the ability to have my exhaust be quiet when I want it to and loud when I want it to. Why would I not want to get what I paid for?

[Lithias]

Sad update, cleaning out the build up did not fix it. I ordered a can of the dry lubricant that was used before, and I'll give lubricating it a try. If it doesn't work, I may do a fuse pull or just live with it.

[Lithias]

Happy update. The lubrication seems to have nearly quieted the squeak. I am going to do another lube of it tonight when the exhaust is stone cold, and I am fairly certain that will make the problem go away.

The TSB that has the work instructions isn't complete. You need to also lube the moving parts on the inside of the exhaust.

This would explain why the lubing had no effect on my first exhaust. This should probably be regular maintenance for anyone with NPP.

I'll update again after a week.

[cskipgo]

Originally Posted by Lithias

Happy update. The lubrication seems to have nearly quieted the squeak. I am going to do another lube of it tonight when the exhaust is stone cold, and I am fairly certain that will make the problem go away.

The TSB that has the work instructions isn't complete. You need to also lube the moving parts on the inside of the exhaust.

This would explain why the lubing had no effect on my first exhaust. This should probably be regular maintenance for anyone with NPP.

I'll update again after a week.

Good to hear its better!