A Beaver County lawmaker is worried that auto garages are gouging customers on the computerized emissions analysis known as "on-board diagnostic" testing, or OBD tests.

So state Sen. Gerald LaValle, D-Rochester, wants to cap the price for the test at $20, plus taxes and fees. He's one of two prime sponsors on an emissions bill to be introduced this week.

"If they're not going to adjust the prices themselves, we're going to adjust it for them," LaValle said.

Right now, testing prices are market-driven and fluctuate from county to county. In Allegheny County, where motorists have been subject to emissions test since 1984, many garages have the OBD equipment, and prices are more reasonable.

On-board diagnostic systems have been installed on all vehicles manufactured since 1996. The system allows a mechanic to attach a cable to a vehicle's on-board computer and download information that can be used to calculate emission quantities.

Even though some garages in Allegheny County have the OBD equipment, most have relied on traditional tailpipe tests. But in Allegheny, Beaver, Washington and Westmoreland counties, the current tailpipe tests for 1996-and-newer vehicles will by June be replaced by the OBD test, because of the new Environmental Protection Agency standards.

The old tailpipe emission tests cost about $28 in the Pittsburgh area, while a shrewd shopper can find OBD tests for under $20 at places such as the Hi-Tech Auto Care outlets along Freeport Road in Blawnox and Butler Street in Lawrenceville.

Craig's Auto Service, in Industry, Beaver County, charges about $23.

But elsewhere, prices are higher. In the state's central counties, where most garages don't yet have the new testing equipment -- meaning the few that do are free to inflate the price -- initial OBD fees are as high as $50. LaValle said that's unacceptable.

"They're charging $40 to $50 for a test that takes about 11 minutes to do," he said.

Thanks to new federal pollution regulations, the emissions testing program is expanding: Before December, motorists in only nine Pennsylvania counties were required to submit to emissions tests. By the end of the year, 25 counties will require them.

So far, legislators have shown little interest in putting price caps on mandated tests, LaValle said, but he hopes interest in his bill will pick up once the new standards take full effect and the prices start affecting constituents across the state.