I'm having the same problem
I'm having the same problem here in Pennsylvania. It's NOT occasionally, like on a "cruise" night (which they have here). It's as you say "24/7". One engine sound dies down and another one comes along. It was not like this 5 - 10 years ago. I wear noise-cancelling headphones when I'm outside. We do have emission testing here in PA -- but it's done at garages...probably the same garages that do the modification. The article talks about the "rights" of people to have loud cars but where's my right to not have to listen to that noise? I choose to not live next to an airport, I choose not to live next to some local industries that have noise, I can't choose not to live next to ANY road. We're sandwiched between two very loud roads that are over a mile away in each direction and I still can here the cars (loudy) over the television and in our bedroom, with the window closed. Yes, it IS depressing...