Q Help! My car just flunked its smog test for too much NOx. I went to one of those test-only smog stations and they weren’t real helpful in telling me what might be wrong and how to fix it. It runs ...

When the word ‘emissions’ is mentioned, most of us will think of carbon dioxide. It has become the measure of how clean or otherwise most vehicles are, but there’s another critically important exhaust ...

The U.S. Environmental Protection Agency (EPA) will be allowed to implement potentially counterproductive smog-prevention regulations after the U.S. Supreme Court on November 14 let stand a lower ...