Owners of smoke-belching cars in Utah County will be getting letters asking them to bring their rigs in for inspection.

The county's Bureau of Air Quality plans to start sending notices in June to owners of cars identified by remote sensors as polluters.The tests would have started sooner, but county officials have been waiting on a part for one of the machines.

"Right now, we're waiting on the generator so we can be confident in our tests," said Terry Beebe, bureau manager. The generator is used to calibrate test equipment to detect the gas that can cause particulate pollution.

Utah County is conducting a federally sanctioned test to determine whether remote sensors and the existing emissions testing program can identify polluters as effectively as the enhanced emissions testing program the state Division of Air Quality recommended in 1994. The county has until May 1999 to determine which system works best.

The test involves using the remote sensors to identify cars that emit high amounts of carbon monoxide and bring them to the test facility next to the county jail for additional tests. The verification tests will be conducted with both enhanced emissions testing equipment and the present emissions testing system to determine which technology is better.

County officials have talked about bringing in people identified by the sensors as air polluters since last summer, but the program's been delayed due to various problems.

Lee Allen, an air commission member and executive director of the Provo-based Citizens for Environmental Common Sense, said the problems show the testing system is not foolproof.

"Every bureaucrat assured us that there would be no problem" with the emissions testing. "I think this would show that the sense of the people in Utah County was right."

Joe Thomas, an environmental scientist with the DAQ's Mobile Sources Branch, said the problems aren't an indictment against the testing technology.

"If you look at Colorado and Arizona's program, they're flawless. It is the benchmark with all good programs," Thomas said..

Thomas said problems can arise because the system is complex and can easily overwhelm someone who isn't used to working with it. He said the equipment in the training center at Weber State University has worked flawlessly for more than a year.

Allen said the air is getting cleaner not because of testing technology or oxygenated fuel, but because the cars driving around Provo and Orem are getting newer and cleaner.