Thieves are stealing catalytic converters from parked cars, as prices of precious metals spike

It took only a few minutes, late at night, as Harvey Briggs was asleep in his suburban Madison, Wisconsin home. Without a garage, he had a brand new Toyota Land Cruiser parked in his driveway, alongside his bedroom window.

"When I woke up, I hopped into the car, hit the ‘Start’ button and it immediately sounded like a NASCAR racer," said Briggs, an independent marketing consultant. "I shut it off, crawled under the car and found the catalytic converter on the driver's side had been cut off" during the night, he told NBC News.

Thefts of catalytic converters have skyrocketed from an average of 108 per month in 2018 to 2,347 in December 2020, according to the National Insurance Crime Bureau. And some estimates suggest the figure may have doubled again this year, driven in part by surging prices for the rare metals used in the emissions control devices.

Platinum, the primary metal, bottomed out at around $622 an ounce early in 2020, but then climbed to nearly $1,300 later in the year. Palladium has fallen as low as $617 an ounce in recent years, but it surged to nearly $3,000 in April, an all-time high.

There isn't all that much of these metals in the typical catalytic converter — between 3 and 7 grams of platinum — but it doesn't take much effort for a skilled thief to nab one of the devices.

"If you’ve got a sharp saw, you can go through an exhaust (pipe) pretty quick" to get the converter, said Lance Maze, service manager at Varsity Ford, in Ann Arbor, Michigan.

Thieves then take the devices to scrap metal dealers before heading back out to steal again, going after vehicles that use the most rare metals in their catalysts, such as the Toyota Prius and other hybrids. They also target pickups and other trucks that sit high off the ground since it is easier to crawl underneath them.

For owners it can come as a big surprise when they fire up their car and hear a loud roar, rather than a muted exhaust note. What might, at first, seem like a worn muffler turns out to be a big gap in the exhaust system where the catalytic converter used to be mounted.

That's only part of the problem. The devices are a critical part of every modern gas or diesel vehicle's emissions control system. As exhaust gases pass through, those rare metals cause unburnt fuel to completely burn off, so what spews out of the tailpipe has a minimum of smog-causing oxides of nitrogen, carbon monoxide and other pollutants. No converter equals lots of dirty air.

What to do? Authorities are cracking down on more unscrupulous scrap metal dealers who intentionally wink and nod when thieves show up with their ill-gotten goods. And that isn't limited to catalytic converters. In recent years, police have reported a rise in theft of all sorts of metal objects, such as copper pipes stripped out of unoccupied buildings, as well as aluminum siding and gutters.

Efforts to crack down on scrap dealers have had limited success, with a bill proposed in the Michigan legislature in 2014 severely watered down by the time it was passed into law. Some locales are now getting more aggressive, however. In Reno, Nevada, the police department and the city's Business Compliance Division are citing scrap dealers who don't keep good records on who they’ve bought from — and then provide that information to the city.

Late last month, authorities in Torrance, California, wrapped up a three-month crackdown on catalytic converter thieves, arresting 20 people.

"The prices for the rhodium or palladium that are in it are so out of control right now," Sergeant Mark Ponegalek, a Torrance police spokesman, told the Los Angeles Times. "The profit margin is too good for the crooks."

Experts offer several ways to reduce your own risk of being targeted.

Parking in a locked garage is the most secure option, especially at night, or use a restricted garage or lot during the day when you’re at work or running errands.

Consider having your vehicle's VIN number engraved on the converter. Some owners are having the converters painted a bright color — using high-temperature paints — that can signal when it may have been stolen.

After the theft of his SUV, Briggs said he plans to install motion-detecting spotlights and a camera outside his home. He hopes that will deter a future robbery or, at the least, help identify a thief.

Some motorists are also installing anti-theft cages and covers that rivet into the underbody of a vehicle. These claim to make it harder for thieves to hack through. But they can also create problems. Catalytic converters run hot when burning off exhaust fumes, and it could pose a fire risk if that heat can't dissipate into the surrounding air. They also could make it tougher to perform repairs, when needed, on a vehicle's exhaust system.

Paul A. Eisenstein is an NBC News contributor who covers the auto industry.