2008 Mack CXU613 Smoke while Regen . Injector or Doc?

Bought a Mack Truck. When it decides to regen while going down the road it starts puffing out smoke when I’m accelerating (getting up to speed and keeping speed) it goes away when I let Off the throttle. Smoke comes from passenger side where the filter is. This seem like the doc is done for or an injector ?

 

Then wouldn’t it do it the whole time ? Not just while doing a regen ?

 

Is there a way to make it not smoke so bad ? Maybe exhaust does have a leak ? It’s look like a freight train when it’s doing it’s regen. Fellas on the cb tell me my trucks on fire LOL. Although it kinda looks like it!

 

Truck does not take def

 

It doesn’t do it unless it’s in the process of the regen. Which seems to happen every couple days. But it just looks like a freight train when it starts