Around here, a deleted truck sells for more than a stock truck.
If you're out of warranty, delete the thing and you have another 300 K before she wears out.
There was a thread comment on deleting emissions equipment a while back and one writer claimed and cautioned that it would result in one driving an illegal vehicle and as such your insurance company could or would claim you are not covered upon having an accident.
I’d at least check into this before deleting.
A friend has a newer duramax that’s deleted def, dpf , egr blocked and with a 65 hp chip upgrade. It is one fine, smooth running truck and will haul azz when you put your foot in it. 19 mpg tank to tank.