A valuable auto part underneath your vehicle is being stolen.

Martin Sarkis, owner of SAGA Motor Vehicle State Inspection, said he’s been consistently noticing victims of catalytic convertor thefts.

"The reason why they steal the catalytic converter is because they have platinum,” Sarkis explained. “And platinum is kind of expensive. So people are [taking} out the platinum. Selling what is inside."

An investigator with a special unit in the Brownsville Police Department said the department has seen these thefts in the past, and victims will know right away if the theft has occurred.

“Their car won't function properly so that's why we ask they call us before they go to a mechanic,” investigator Tamayo said.

The thefts typically happen at shopping centers, movie theatres and even driveways.

"It's going to make a lot of noise because it's like you don't have any muffler on the car,” Sarkis said.

In a front wheel drive vehicle the catalytic convertor is usually inside the engine bay -but it’s usually right underneath the engine on a rear or all-wheel drive. Cars are required by federal law to have one and it’s bad for the environment if cars don’t have them.