Yep. Actually, since most cars on the road are now equipped with computerized electronic fuel injection, unburned hydrocarbons are a much smaller problem than back in the days of carbureted engines and overdue tune-ups.
If eliminating CO2 is a real priority, the best thing we could do is take a hacksaw to our catalytic converters. The states should lead the fight against greenhouse gases by legislating away the "exhaust sniffer" component of annual safety inspection. Why, it's their carbon-neutral duty to do so!