The Pennsylvania Automobile Service Providers accepts the switch to on-board diagnostics, said Chris Chrisman, the group's president. Provisions in the legislation will help the transition. One establishes a fund to reimburse garage owners for a portion of the money they spent on tailpipe equipment, which the bill is making obsolete. And the bill phases in the new system. Tailpipe emissions will continue for older vehicles until about 2009, when their numbers dwindle to 20 percent of all vehicles on the road.
Some environmental groups see on-board diagnostics as a promising technology.
But others, such as the Clean Air Council, aren't sold on it. Kim Nicholas, a policy analyst with the statewide group, worries that it might produce false readings, allowing poorly running vehicles to pass the test. And her group opposes the idea of allowing older vehicles to go without any emissions screens at all. They were built under less stringent emission standards, she said, and therefore cause more pollution. On-board diagnostics determines whether the engine is burning fuel cleanly and tests other auto systems, such as the transmission.