Skip to content


Cat Converter Security Devices Reviewed

19 Jul 2022 7 Comments

Please check out a review of catalytic converter security devices here. Donut Media put some of these devices to the test!



Catalytic converters can cost more than $2,000 and can be stolen in less than two minutes. For owners of vehicles that use multiple catalytic converters, being targeted by catalytic converters thieves can be an exorbitant experience.

There are several security devices to prevent catalytic converter theft with varying effectiveness. To cut through the confusion and help you decide which security device is right for your vehicle, we’ve reviewed the most common types.

Underbody Catalytic Converter Strap/Wires (Cat Clamp)

The underbody strap or wire security system is a series of steel cables that enshroud a catalytic converter in a cocoon of stainless steel wires. Depending on the brand, it may or may not be wrapped in some type of heat shield-resistant wrap. Although the cables are fairly tight next to the catalytic converter, the small amount of movement coupled with the strength of the steel cables makes it difficult to saw through.

These can be difficult to fit to cars that are very large or very small. For full-sized pickups, there may not be enough material to protect a catalytic converter entirely. In smaller cars, excess material can cause a problem as it has to be safely stored somewhere out of the way of moving parts – the cables can’t be trimmed to suit.


  • Difficult for thieves to cut through
  • Product is resistant to rust


  • Doesn’t fit every vehicle
  • Can be difficult to install  – a lift and multiple people are recommended for ease of installation
  • Cables can rub together to make a rattling noise when the car is driven
  • May have to modify it to fit some vehicles
  • Looks messy if the car is viewed from underneath
  • May be able to be cut through with an angle grinder (but will likely stop a Sawzall)
  • Multiple kits will be needed if your vehicle has more than one catalytic converter
  • The limited space surrounding some vehicles' exhausts can make this product difficult to install.
  • If the cables become loose they could potentially catch on debris, damaging the underside of the vehicle

Underbody Catalytic Converter Alarm

There are several different types of underbody alarms designed to protect against catalytic converter theft. Most commonly, an alarm is wired to a motion detection sensor that activates when the exhaust system is jostled or motion is detected. We have also seen alarms that are heat sensitive and activate when a sudden temperature change is detected.

These can be installed on vehicles and may or may not need specialized tools. The most effective catalytic converter security systems are usually custom-made to fit a particular model of vehicle and are much more difficult for thieves to bypass. But the extra security can come with a higher price tag due to increased engineering and manufacturing costs.


  • Relatively inexpensive
  • Universal fit (almost)


  • Some have to be manually armed and disarmed
  • Not waterproof and computer components can be sensitive to moisture
  • Potential for false alarms and could be set off by animals
  • Motion sensors may need wiping/cleaning regularly to avoid degradation

Anti-Theft Catalytic Converter Stickers

Anti-theft catalytic converter stickers affix to a car window warning that the catalytic converter is fitted with a security device. They are best used in conjunction with other catalytic converter security products to provide a visual deterrent to would-be thieves. The printed warning may indicate the fitment of a GPS tracker, engraved part, or other theft deterrent system.

Although cost-effective the largest problem with anti-theft stickers is they need to be displayed in a very prominent area and even then, catalytic converter thieves working underneath a vehicle may not even look for or notice them.


  • Visual deterrent for thieves
  • Possibly the cheapest option available
  • Can be attached anywhere and to any vehicle


  • Difficult to see at night
  • Able to be peeled off
  • May fade in the sun
  • Thieves can potentially not look for them
  • Offers no physical security system to prevent catalytic converter theft
  • Easily bypassed or ignored

Catalytic Converter Shields

Catalytic converter shields (often called cat shields) are a physical metal barrier that attaches to the underside of a vehicle, covering a catalytic converter. The best ones on the market will come with, or have an option to purchase additional security hardware such as tamper-proof screws. These shields often require installation by a professional as they take advantage of the structural rigidity of a vehicle's chassis to make them difficult to remove by catalytic converter thieves.

When buying a cat shield consideration must be given to the type of material used. Some shields are made from aluminum, which is a lighter, but a less dense material. Conversely, catalytic converter shields made from 304 stainless steel are not the cheapest but is a more dense and rigid material and are difficult to cut through. 304 stainless steel and aluminum is also resistant to oxidation for corrosion resistance which is important given a cat shield sits underneath a vehicle and is regularly exposed to road grime, rain, and snow.


  • The best catalytic converter security system for your vehicle
  • Rust resistant
  • Can be fitted with optional extras like tamper-proof screws for even greater security
  • Incredibly difficult to cut through
  • Arduous to remove or bypass by thieves
  • Can be easily removed with the supplied security key


  • Not all catalytic converter shields offer the same level of protection
  • May need to be installed by a mechanic

How To Choose The Right Catalytic Converter Security Device For Your Vehicle

Now that you’ve examined the most commonly used security devices against catalytic converter theft, choosing which one is right for your vehicle comes down to the level of protection you need, and your budget. Owners of highly targeted vehicles like the Toyota Prius and Toyota Tacoma may opt for better-than-average protection as thieves learn how to bypass cheaper devices.

Price isn’t everything, however. A good security device will be designed to suit a specific vehicle, made from material that can’t be easily cut through and can’t be easily bypassed or removed.

Get the ultimate in catalytic converter protection or free advice from our security experts here


Prev Post
Next Post


20 Feb 2023 Pablo

I own a tacoma and mi friend does as well. Yesterday his cat got stolen in front of his house in tampa florida. The police said thats the 7th cat this month on this area.

28 Dec 2022 SARAH T DINH

I am looking for cat shield for my 2022 Lexus RX 450h

28 Dec 2022 Richard Baldelli

What shield do you recommend for a 2017 Mazda CX-5

28 Dec 2022 Mary santoro

I have a 2002 Lexus and have 3 convertors ’ is there a shield for my car

28 Dec 2022 Paul Leroy

What is a good anti theft device for my2016 santafe sport cat converter

Leave a comment

Please note, comments need to be approved before they are published.

Thanks for subscribing!

This email has been registered!

Shop the look

Choose Options

Edit Option
Back In Stock Notification
this is just a warning
Shopping Cart
0 items