Exhaust pausing

[Darren2021gmc]

So I have a 2021 gmc sierra elevation  with the 5.3 I have put a outlaw series cat back duel exhaust it sounds great I have auto stop turned off and I'm buying the shut off for it to put in the dash so I do not have to press it all the time but I have it off and when I am comming to a stop sign or slowing down it seems to cut the noise to my exhaust and it then when I come to a stop seems to build the pressure to alow it to make noise again I was not sure if there is a tune for this or something I need to do or get but if I stuck with that I mean I'll just live with it but if anyone has a solution to it would be greatly appreciated. 

[Firehawk99]

It is the DFM working. If you get a range pulsar LT or just their disabler it will get rid of it. Try putting the truck in M and shift to L9 and come to a stop. I bet it won't do it anymore.  By putting it in L9 it also shuts off the DFM.

[kodiakdenali]

I'm not sure exactly what you're referring to, but I wonder if this is the sort of thing you are hearing? Notice the major difference between the engine braking sound with vs without DFM, to go 25:00 in the video