Stealing catalytic converters is a growing problem and an expensive repair for victims.
But there are some things you can do to fight back and maybe help catch the bad guys.
Houston police say the crooks are stealing catalytic converters because the rare metals inside are worth hundreds of dollars at scrap yards.
HPD says there is a way to help them catch the suspects.
"One of the prevention tips that is very inexpensive is simply purchasing a small engraving tool and engraving the last eight of your VIN number or at least your license plate number into the catalytic converter," said HPD Sgt. Tracy Hicks.
That way if your catalytic converter is recovered during an investigation, police can track the rightful owner.
But getting under a car can be difficult for most of us, so ask your mechanic to do the job. It should be an inexpensive task.
"Probably $10 or $15. I can't see where it costs that much," said Mike Poutous of Poutous Auto Repair.
There are some ways to keep catalytic converter thieves from removing the devices in the first place.
HPD says consumers can put a specially made steel cable around the catalytic converter or a wire cage that makes it harder for thieves to cut through the exhaust system pipes.
But the most protection may come from a metal plate that is bolted to the bottom of a vehicle.
The metal plate runs about $150. The wire cage is closer to $200.
You do have to get under the car to install it, so if you can't fit, ask your mechanic to do the job.
The price will vary on what kind of vehicle you have, but it will be much cheaper than replacing a stolen catalytic converter.