‘Cat’ Stolen From Your Car? It’s a Growing Crime Trend.

In December of 2021, David Aujero walked out of his home in Ditmas Park, Brooklyn, got into his 2002 Honda Element, and turned on the ignition. The sound that came from his car was a rumbling roar, as if someone had swapped his engine with that of a dump truck. “I thought maybe the car had to warm up a little, but the sound was really loud,” said Mr. Aujero, a video director for technology brands.

When he took his Honda to the repair shop, the mechanic knew what was wrong before Mr. Aujero stepped out of his car: His catalytic converter had been stolen. “It was the fourth case my mechanic had seen that week,” he said.

Catalytic converters, or “cats” for short, are valuable because they contain precious metals that can be extracted and resold for up to $50 per gram. Nationwide, thefts of the device increased by well over 1,000 percent in 2019, according to a report from the National Insurance Crime Bureau.

In New York City, reported thefts jumped from 2,070 to 7,000 between 2021 and 2022, according to a New York Police Department spokesman. The incidents were equally distributed throughout the city, with the highest overall numbers recorded in the Bronx, Queens, and south Brooklyn. Just this week, police officers interrupted a theft in progress — the person apprehended was using a large power saw — in Washington Heights.

Kevin Wright, a mechanic in Midtown, who said the problem had not been this bad in 20 years, blamed the pandemic. John Mouras, another mechanic in Greenpoint, agreed. “I figure it’s a lot of people not having work and trying to find a way to survive financially,” he said. But there is also evidence that the robberies have ties to organized crime. In November of last year, the Justice Department busted a nationwide ring of “thieves, dealers, and processors,” seizing $545 million in assets from 21 people, including two men from Long Island.

The device, which looks like a metal hot water bottle, is found in the car’s underbody and is part of its exhaust system. It has been standard in nearly every vehicle manufactured since 1975 because of the Clean Air Act. It converts harmful emissions like carbon monoxide into safe ones like steam through the use of a chemical catalyst (hence the name).

The magic ingredients of that chemical catalyst are the precious metals rhodium, palladium and platinum; the latter two cost between $30 and $50 per gram. Each converter contains several grams of each metal and can fetch as much as $1,000 at unscrupulous scrap yards. The converters can be clipped off a car with a battery-powered saw in minutes, and thieves can pick off entire rows of vehicles in under an hour.

Mimi Pak had her converter clipped from her 2012 Toyota Prius in the summer of 2022. She had driven to Astoria, Queens, from her home in New Jersey to visit a friend, parking on a quiet residential street for just a few hours. But when she came back and started up her car, a sudden, off-putting roar came from the tailpipe. “It sounded like a Harley Davidson revving right outside my window,” said Ms. Pak, a teacher. “I waited for it to pass me on the street but realized that the sound was coming from my car.”

Ms. Pak took her vehicle to a Toyota dealership to have the part replaced last August, but she was told it would be months until the part was available. Catalytic converters on hybrid cars are especially attractive to thieves, as their reduced emissions mean less wear on the palladium and platinum catalysts.

Global supply chain issues surrounding the precious metals have been an issue since the onset of the pandemic, and now there are concerns, stemming from the Russia-Ukraine War, that Russia, which supplies 40 percent of the world’s palladium, according to Moody’s analytics, could pull its supply off the market. “My converter got stolen in August, and I just got my car back in January,” Ms. Pak said.

As a preventive measure, the New York Police Department has created a system in which car owners can etch a serial code into their catalytic converters and enter it into an online database. Still, that hasn’t made thieves any less brazen. In 2021, Dan Segal and Lana Samad were preparing to drive across the country in a 1999 R.V. when their catalytic converter was stolen outside an auto body shop in the Bronx the night before they were scheduled to leave.

“We came back in the morning to pick up the R.V. and our mechanic was panicked. They had caught the whole thing on video,” said Mr. Segal, a management consultant who now lives in Oakland, Calif. “It was just one guy with an electric saw at 4 a.m. who was in and out in less than a minute.”