Five catalytic converters have been stolen this week on the South Shore.

A South Lake Tahoe resident started his 1994 Toyota pickup Tuesday morning and immediately heard an unfamiliar loud rumbling sound. He thought the muffler had fallen off. He discovered the loud exhaust sound was unrelated to his muffler, but was actually due to his missing catalytic converter.

Three of these thefts occurred in South Lake Tahoe and two in El Dorado County. In each case, the thief crawled underneath the vehicle and used some sort of cutting tool to remove the converter, according to officers.

A catalytic converter functions as part of a vehicle’s exhaust system. As poisonous and polluting gasses collect within its chamber, the precious metals inside the converter “catalyze” a chemical reaction that alters them into less harmful and cleaner vapors. This reduces harmful exhaust emissions by up to 90 percent.

Thefts of catalytic converters are on the rise across the country, according to officers.

“Thieves are looking for these devices which have ceramic cores coated with platinum, rhodium and palladium. Crooks turn in the metals for cash at metal recycling centers,” police Sgt. Brian Williams said in a press release.

Anyone with information is asked to contact Detective Jeff Roberson at the South Lake Tahoe Police Department at (530) 542.6100.