CO2, the stuff that has been buried for millions of years, and we're releasing all at once into the atmosphere? The stuff that is warming our planet faster than we, or nature, can adapt to? The stuff that is worsening global wildfires, flooding, retreating glaciers, heat waves, desertification, etc.?

Yeah, that stuff. And other nasty things in the exhaust as well.

no, we already abolished all rule making and review about CO2, this is removing the EPA requirement to install scrubbers for removal of NO and NO2 given sufficiently large outputs, which cause acid rain and are linked to respiratory problems. of course it all depends on the dose, which is why there there is a review process, which I guess was just too inconvenient