In a move aimed at reducing unexpected emissions increases and lowering repair costs for motorists, the Air Resources Board has required car makers to make the "brain of modern electronic anti-smog systems more durable and capable of diagnosing engine problems, starting with the 1988 model year. 

The rule adopted at the Board's April 25 meeting in Los Angeles, requires car makers to extend the warranty on oxygen sensors, the most critical component of anti-smog systems on new, high-tech automobiles, from 30,000 to 50,000 miles. The regulations also make installation of on-board diagnostic systems, already in use on some cars, mandatory on all cars equipped with electronic emission controls, beginning with the 1988 model year. These systems also will include a warning system to alert car owners of needed maintenance or repair of anti-smog systems before failures can increase pollution or cause costly engine damage. 

ARB Chairman Gordon Duffy noted that oxygen sensors on 60 percent of 1984 model cars are already warrantied for 50,000 miles and that on-board diagnostic systems also are used by many manufacturers, notably General Motors, Chrysler and Toyota. 

GM, for instance, has already manufactured 20 million cars since 1980 with systems similar to those required by the ARB. "This regulation will make the laggards catch up to the rest of the industry," Duffy said. 

The changes are expected to make cars run cleaner for most of their road life, both by making a key component of the anti-smog system more durable and by alerting car owners to mechanical problems that, if undetected, can cause pollution 5-10 times greater than normal.

"There are as many as 15 engine components that affect emission levels and that can be linked to the on-board diagnostic system to trigger a warning signal if something goes wrong with the anti-smog controls," Duffy explained.

"Without that warning, motorists can drive a high-polluting car without being aware of it," he said. 
"Because on-board computers in present day high-tech automobiles maintain car performance and fuel economy even when key components of the auti-smog system fail." 

Although cars meet emission standards when they roll off the assembly line as many as 10 percent become high polluters within 10, 000 to 15,000 miles of driving instead of staying within emission standards for the required 50,000 miles. Much of the problem is blamed on poor maintenance, mechanic error and lack of durability in anti-smog components. 

Recent studies by the Federal EPA show that oxygen sensors, which monitor exhaust levels and constantly adjust the air/fuel mixture to help keep emissions low, have a high failure rate and can cost car owners from $75 to $125 to replace if they are not warrantied for the full 50,000 miles. In addition to eliminating that expense, the new regulations are expected to lower repair costs by making diagnosis of mechanical problems easier. 

The on-board diagnostic systems will help mechanics identify faulty emission controls by reading a code through a blinking warning light on the instrument panel. Major components linked to the system include the computer that runs the anti-smog system, fuel metering devices, the exhaust gas recirculation valve (EGR) and many other electronic sensors used to measure temperature, barometric pressure and other conditions that influence emission levels.

To keep repair cost low, the new regulations require the on-board diagnostic systems be designed so that most of the garages licensed to work on anti-smog controls can use the system without special tools or costly readout instruments, in most cases mechanics will be able to trace faulty anti-smog systems by matching the code of blinking lights in the system with instructions in the repair manual. 

Also, because the diagnostic and warning systems can be added to existing electronic emission controls, the Air Resources Board estimates that the cost to manufacturers will be no more than $30 per car and, in many cases, much less. 

"We don't need new technology to make cars cleaner in the near future," said Gordon Duffy. "We need to make the technology we already have work better and longer.

"For some time now the old bolt on anti-smog systems have been replaced with electronic computer driver pollution control that are a basic part of the car's design", Duffy said.

"Those changes have increased performance and gas mileage but have also made cars more complex in that direction and certainly reflect changes that the industry has already begun to make." 

This rule change will help simplify repair work on these cars and is the biggest step the ARB has taken in a new direction to make cars cleaner for most of their road life.