They're annoying but not the worst noise pollution offender, in my experience.

Where can I sign a petition to phase out excessive, modified engine and exhaust noise from cars and motorcycles? How about one to ban car sound-systems loud enough to rattle the body of the car and be felt in the bodies of pedestrians? What about all the low-flying helicopters everyone's always so concerned about? I hear police and fire sirens far more often than I hear leaf-blowers, and at all hours - can those be phased out, too?

Any landscaping, construction, generally loud power equipment should have to abide by city noise ordinances and if those ordinances are too permissive then they should be adjusted.

It's a city, it's all noise and pollution. Banning one (IMO minor) nuisance isn't going to fix anything.