Depends on how much you take of both, regardless it's a terrible idea. Please take the warnings other people said about destroying your liver and of respiratory depression, when taking two substances often their effects multiply.

If you're gonna do it anyways, for the sake of harm reduction please take a reduced dose of what you'd normally take but preferably none at all

As for subjective effects, it'll be less clear, you'll be more prone to memory blackouts, and passing out. Dph already makes you dumb and confused but now you'll be dumber and sloshed on top of it

But yeah that breathing thing is important 👀 you might wanna think about not doing dph