Pennsylvania should change its emissions testing to meet air quality goals, auto shops say. A faulty device is making that tougher.

Auto mechanics are experts at diagnosing problems — a sputtering engine, squeaky brakes, a warning light that just won’t turn off.

So when a group of representatives for auto shops gathered in Norristown last week to warn Pennsylvania’s Department of Environmental Protection of a problem brewing in the state’s emission testing program, they had the room’s full attention.

Since the late 1990s, Pennsylvania has required mechanics to test heavier vehicles — including many SUVs, work vans, and pickup trucks — for harmful pollutants, using different tools than lighter cars.

But those tools are now decades-old, shops say, and this year, many are reporting that theirs are beginning to fail and can’t be replaced.

“We do not have enough equipment to do our job in our industry,” said Dave Preston, a garage owner and member of the Mid-Atlantic Auto Alliance. “What do you tell a customer that needs a test? ‘We have no equipment to test your vehicle?’”

With more advanced emission testing methods widely available, shop owners like Preston say manufacturers have stopped repairing old testing tools, or have gone defunct altogether over lack of demand.

That’s leaving Pennsylvania garages with a tough choice: scramble to find increasingly-rare replacement parts, or send potential polluters back on the road without an inspection, harming the region’s air quality.

For decades, Dilworth Coffman’s family has used the same tools to perform emissions tests at their Warminster, Bucks County, garage.

Since Coffman took over for his father over a decade ago, however, the tools the Pennsylvania Department of Transportation requires him to test heavier vehicles — a dynamometer and a gas analyzer — have frequently been on the fritz.

In 1997, when Pennsylvania set regulations to clean up its air, it mandated that shops like Coffman’s Service perform what’s called a two-speed idle test on any vehicle weighing between 8,501 and 9,000 pounds.

It may seem like an arbitrary number, but Coffman said that at the time, heavier vehicles often lacked the onboard computer technology that have since become an industry standard for emissions testing.

These days, Coffman can test most modern cars — including heavier ones — using an electronic scanner that plugs into a car’s onboard computer.

What hasn’t changed is the law.

Coffman is still required to perform the two-speed idle test on heavier vehicles, placing a handheld sensor over the tailpipe to check for pollutants while simulating different road conditions.

Whenever Coffman’s tools wore down, he said, their manufacturer would reliably offer him replacement parts.

Until he called this year.

“Bottom line is, I can’t buy a machine,” Coffman said. “I can’t fix this one, and they keep telling me I have to send my customers somewhere else to get their emissions done. I would love to fix it or buy a brand new one. There’s none available.”

Craig Yetter, a spokesperson for PennDot’s driver and vehicle services, acknowledged auto shop owners’ concerns in an email.

“PennDOT does recognize that due to the age of the equipment, some manufacturers are electing to no longer support the equipment, and we will therefore continue to closely monitor the situation,” Yetter wrote.

However, Yetter said shops aren’t required to perform the test if they don’t want to, and that the department believes there are currently enough remaining shops that can offer it.

Ron Turner, director of the Mid-Atlantic Auto Care Alliance, has spent years urging lawmakers in Harrisburg to ditch tailpipe testing on heavier vehicles in favor of onboard computers.

While the two-speed idle test was once widespread, Pennsylvania is one of the only states that still mandates it, according to Turner.

California, Colorado, and Maryland still require the test, though in those states it’s only for vehicles built before 1996 that are likelier to pollute.

That share of vehicles is rapidly shrinking, so much that in 2016, New Jersey eliminated tailpipe testing entirely, saying there weren’t enough vehicles built before the mid-1990s still on the road.

Pennsylvania is unique, according to Turner, in that it requires tailpipe testing for vehicles built after 1996, when onboard computers became the norm.

Lawmakers in Harrisburg are loath to change the state’s air-quality guidelines, according to Dave Preston, fearing that one change will lead to further revisions.

“You’re opening up the whole thing,” Preston said, “It’s like changing the Constitution.”

But after the Environmental Protection Agency released a report last year finding that Philadelphia had surpassed its standards for ground-level ozone, Preston and Turner are hopeful officials will soon change their stance.

The federal government has tasked the state DEP with tamping down dirty air by August 2024. In Norristown, the department was fielding suggestions that could eventually inform changes to law.

Besides ditching the tailpipe test, for example, the shops said they would like to see onboard computer testing required at garages statewide.

With less concentration of people and cars, rural counties are not required by PennDot to tailpipe test heavier vehicles, a departure from the rules that apply to Philadelphia, its suburban counties, and the Pittsburgh area.

Turner believes this makes testing less reliable in those counties, allowing dirty air to drift from other parts of the state into Southeastern Pennsylvania and making EPA compliance tougher to secure.

Coffman’s two-speed idle tools were already overworked when they began to break down this year.

As dealerships and small garages struggled to repair their own tools, they began referring customers to Coffman.

Other shops, he said, are sending drivers of heavier vehicles out the door uninspected.

Coffman prides himself on service. He doesn’t want to turn away drivers in need, often small contractors who need to inspect the pickups and small vans they use on the job.

“Nobody knows what to do,” Coffman said. “Honest to God, everybody’s cheating. And I don’t want to lose my license. That’s what I’m up against.”