You can do a "DEF delete," but if you are caught you will be paying some major fines for EPA violations that will quickly exceed the value of the truck.

Do the DOT inspections at weigh stations not check for this? I know that older trucks are grandfathered as they never had it; generally vehicles are required to have all the original emissions controls intact.

You also will need to know how to reflash the engine computers, which will not be happy if expected emissions equipment is simply removed.

I think the point is that if there's a urea shortage, good governments would waive the DEF requirement until it ends, rather than effectively saying "sorry, it's illegal for you to drive that truck at any price".

> I think the point is that if there's a urea shortage, good governments would waive the DEF requirement until it ends,

Automotive EE here, this will ABSOLUTELY NOT happen.

Oh, I have no delusions that it will happen. I also have no delusions that our government is good.

It obvious possible to run diesel with out DEF.

And you “can” remove the def systems and cats.

But the real story is that all diesels on the road now use DEF/EGR systems and that isn’t going to change because of a shortage.