WeGone

I'm going out on a limb here but have you tried to disconnect the negative cable to reset things? Do you have a code reader?

Thanks for your input, but I did not buy a 6.2 for gas mileage plus @ less than 8k miles a year its no big deal for me.

I would try your local GM dealer parts department.

Wow That sux, Hope they get it sorted out and get you back on the road ASAP.

On my 2021 its listed as UTJ- Theft-Deterrent System on the build sheet.

I only have 1 and it is clamped open, not much change in sound if any except at idle. If you watch its operation as the motor warms up it does close some but opens again as you increase throttle. It appears to open completely at high idle during start/warm up than slowly closes as idle rpms decrease.

If your referring to the arm you see at the left side of the pic it is the old guy assist handle...LOL

GM must be watching this site... Mine updated this AM LOL

I keep reading about these updates, I wonder what prompts them as not everyone is getting them? Mine is a 3/21/21 build with version 153.

Have you tried disconcerting the battery negative cable?

Maybe its a GMC thing. Have a 2021 Silverado LTZ that has it with standard mirrors.

Have not seen a way to display that information. I also miss the DFM display.

When removing the muffler and flapper are you guys/gals also removing the resonators at the end? or do you even have them? My 2021 6.2 has them.

Both are plug and play, Both look like the can be broken fairly easy as they are just plastic.. the tailgate fix looks very close to were the safety chain hooks. Curt looks as if you were off just a bit backing up to your trailer you would brake it off. Looks like a simple switch that would trip when the hitch is slid into the receiver would be better. I suggest anyone interested watch both install videos.

Just wanted to update this. I installed TheSpringThings July 2nd at the time I had about 500 miles on my Z71. They worked great completely stopped the noise. Now I'm at 2700 miles and it has returned. Good thing is its not as pronounced or lets say a more subdued muffled sound.