Catalytic converter thefts have increased dramatically as the value of the precious metals in them has soared. “Cats” as they are commonly referred to, contain rhodium, palladium and platinum, some of the most expensive metals by ounce. And given their relatively easy to access location on the underside of vehicles, many unfortunate car owners are finding their cars without this critical environmental component of their engines. Lawmakers in 18 states are proposing limits to the sale of catalytic converters in hopes of curtailing the issue.