bill i hope youre kidding. pollutants from cars are the least of our worries heading into the 21st century. coal plants have a much more drastic effect on the environment. and please dont retort with how new cars are becoming more efficient with hybrid electric etc etc. the main reason for this is we (the united states) is moving in a direction that makes us less dependent on the middle east for oil. yes there is smog that covers most big cities throughout the united states and yes a large percentage of the smog is caused by car exhaust however that same smog is not really damaging the environment in the same way other toxins are destroying the ozone layer. basically people are more at risk for sickness because of acidic rain water etc but the same people are more at risk for developing cancer or some other ailments by inhaling second hand smoke. therefore the affect that a test pipe has on the environment is similar to that of a man pissing in the ocean to bring up the tide.

long live the testpipe!