How To Prevent Catalytic Converter Theft: The No BS Guide.

by | May 3, 2021

Gearist is supported by readers like you. When you buy through links on our site, we may earn an affiliate commission. Learn More.  Thanks for your support!

I’m going to tell you what no one wants to hear about protecting your catalytic converter from theft. 

You can’t.

Where you park your car won’t make a difference and where you live doesn’t matter.

Depending on your car alarm to stop catalytic converter theft? It won’t

Drive an old beater you think no one wants? The thieves don’t care. (This happened to me.)

Even if your car isn’t on the “most stolen catalytic converter” list, it can happen to you.

So, what’s the best form of catalytic converter protection?  Well, it depends.

Much like the rest of life, catalytic converter thieves come in all levels of skill and preparation. If you add the right opportunity, there’s not much you can do to protect your car’s catalytic converter from being stolen.

But there are three main strategies to significantly reduce your risk. The best way to prevent catalytic converter theft is to explore the solutions below and see what will work for you.

Strategy 1: Park in a safe, well lit place with lots of traffic

This is a good idea in general.  Not only to protect your catalytic converter, but to stop other crimes of opportunity. 

However, thieves are getting more bold.  With the right combination of thief and vehicle, a catalytic converter can be stolen in less than a minute.  And it seems that bystanders either don’t notice whats happening or won’t get involved.  I’m sure you’ve seen the videos.

However, most thieves would rather work in the dark and away from a high-risk situation. 

So yes, go for the safe, well lit area over the dark quiet alley.

If you park your car in your driveway, install some motion sensor lights (they’re cheap nowadays) and try a car alarm with a tilt-sensor and vibration detection.

If you don’t want to spring for an expensive catalytic converter alarm install, we’ve seen an increase in people buying a couple of these inexpensive, self-contained motorcycle / bike alarms, and sticking them under the hood or under the car near the exhaust. For around 30 bucks or so for a twin pack it may be worth a shot. These may be the cheapest catalytic converter alarm on Amazon!

This stuff is much cheaper than than the cost of a catalytic converter. It will help give you a heads up if someone is poking around around your vehicle.

Unfortunately, a camera won’t do much for stopping theft, but it may help the police after the fact. At the very least you’ll have a video to show your friends or put on YouTube to show that this is a real concern.

The best bet: if you have a garage, clean out all of that old sports equipment and park your car in there instead!

Strategy 2: Install a catalytic converter anti theft device

Thanks (or no thanks) to the increase in catalytic converter thefts there are several different devices on the market that can add a layer of physical protection to your catalytic converter.

If your car is parked in a crowded place, most thieves won’t run the risk of spending the extra time to defeat one of these devices and move on to an easier target.  That’s the best you can hope for, but it’s a good strategy. Depending on what vehicle you drive, you may have some choices.

Here are the top 4 catalytic converter shields, locks, and cages commercially available.

Each one uses a different design to protect your catalytic converter, and ranges anywhere from $130 all the way to $270+ depending on what you choose.

So, what is the best catalytic converter anti theft device? That’s a tough question.

For every device listed here, i’ve seen both the pros and cons of each. If it was my money and I was protecting a Prius or an Element, I’d go for one of the cat shields. Anything else would get a CatClamp.

Whichever way you go, something is better than nothing…you want to make it as difficult as possible so the criminals move on to an easier target.

The CatClamp

The Cat Clamp is a unique device that uses a combination of clamps and cables to create a type of catalytic converter cage.

This cage acts like lock around your catalytic converter, providing a substantial visual deterrent and physically making it very difficult for the casual thief to steal your cat converter.

I installed one on my old Honda after i replaced my stolen cat converter, and I sleep much better at night. You can read my catclamp review here.

The CatClamp is a universal fit, and people have been able to use them on anything from Honda Civics, Toyota Tacomas, Ford Excursions, Honda CRV and fleet vehicles like Ford F150s and Chevy Express vans. 

One downside of the CatClamp is that installation can be difficult at home, but totally doable. The only special tools you’ll need are included with the kit. If you can change your own oil or are mechanically inclined, DIY install is within your reach.

If you’re not familiar with safety procedures or are uncomfortable working under your car, it’s best left to the pros.

Some people complain of rattling after installation, but that’s usually due to an install issue along the way.

Miller CatShield or CCM Cat Security Catalytic Converter Shield

If you drive one of the high target vehicles like the Toyota Prius or Honda Element, you can buy one of several catalytic converter shields to protect that Toyota Prius catalytic converter.

A cat shield is a plate of metal that attaches to the bottom of your car and guards your catalytic converter. It’s a little like a skid plate you’d find on an off-road truck.

The two big players in this market are Miller Cat Shield and CCM Cat Security. Both are easily available, at least in the US. You can buy the Miller Cat Shield directly from the manufacturer, and the CCM CatSecurity on Amazon.  There are a few subtle differences, but they’re pretty similar in design.

December 2022 UPDATE: MillerCat heard about us and has offered us a discount code to pass along to our readers. Order your CatShield direct and use Discount Code : GEARIST

Since we first wrote this article, MillerCat has expanded their line up. They now include the following vehicles:

  • Toyota Tacoma, Tundra, 4Runner, Corolla, Prius, Sequoia and the Toyota RAV4 Hybrid & Prime
  • Lexus CT 200h
  • Honda Element & The 2003-2007 Honda Accord

I like the Miller Shield a little better because of the fastening system AND they make a Stainless Steel version. Stainless is just a little more expensive, but has a higher cut resistance than aluminum models.

Catalytic converters use high heat to do their job, and Miller has also done thorough testing on their products to insure that your catalytic converter doesn’t damage itself due to extra heat buildup.

millerCat toyota prius catalytic converter protection

Photo by MillerCAT

Here’s a MillerCAT Cat Shield on a Prius V. Notice the louvers to promote airflow to reduce heat buildup. Although professional installation is suggested, If you’re comfortable changing your own oil you shouldn’t have a problem installing this yourself. Always follow safety procedures or contact a professional.

Both companies focus mostly on making Toyota Prius catalytic converter shields and Honda Element catalytic converter shields.

MillerCat has expanded their line up to include Toyota Tacomas, Tundras and Sequioas.

Because they’re model specific to your Prius or Element, installation is fairly straight forward. Both require some minor drilling for install.

If you’re installing at home and have a limited toolbox, you may need to buy a RivNut tool with short handles (Miller CatShield) or a regular old rivet tool for the CCM CatSecurity Plate. The short handles help with the limited clearance when you’re crawling under your car.


This device is a little different than the others.  The Cat Strap is the least expensive of the bunch, It’s basically a series of cables in a sleeve that you glue onto your catalytic converter and exhaust pipe. Like the CatClamp above, the cables make cutting off your catalytic converter more difficult.

The downside it doesn’t look like a substantial physical deterrent like the other options. They do provide a sticker that a thief probably won’t see when under your car in the dark, but every little bit helps.

You can also pair this with the CatEye Electronic Catalytic Converter Alarm. The Cateye is a motion sensor alarm just for your catalytic Converter. I really like the thought of this and you can purchase this separately from the CatStrap.

The Catstrap has the easiest setup for a DIY protection installation. Out of the box it requires no special tools. It uses a heat activated adhesive, kind of like a peel-n-stick setup. They do recommend adding on some additional generic clamps as additional “hard” protection.


The Catlock is another clamp and cable device catalytic converter lock, although not as substantial as the CatClamp. They were available on Amazon, but it seems that they’re not available there anymore.  I can’t find the Cat Lock for sale any place else.

DIY Catalytic Converter Lock

It seems that there are some resourceful people out there coming up with their own DIY solutions.  Most of them involve rebar in one way or another. 

Some weld a piece or two lengthwise (like the Catstrap above) to provide more cut resistance. Others go all out and make their own rebar catalytic converter cages. 

If you’re handy with those kinds of things, go for it.

Whatever you do, do not weld your catalytic converter to the frame or make a hard, inflexible connection. Your exhaust system is designed to move around a little bit, and that hard connection can cause other issues down the road with other components.

Strategy 3: Get Rid of your Catalytic Converter

The only real way to prevent your catalytic converter from getting stolen is not to have one! That means buying an electric car. Seriously though, If you’re not ready for an electric car- try the two things above to keep your catalytic converter where it belongs.

Questions? Comments? Tell us below!




  1. Jeffrey

    I drive a Ford E350 bus. This week my catalytic converter has been almost stolen twice. I’m looking for some kind of theft deterrent. Any suggestions?

    • Jay

      Hi Jeffrey.

      I’m assuming your e350 bus is on a van cutaway chassis? The only off the shelf option that stands out is the CatClamp Maxx. However, with the e350 you have the advantage of having an actual frame instead of unibody construction like most passenger cars and SUVs. That opens up alot more room and attachment options for a DIY / homebrew solution, like a rebar cage to protect your catalytic converter.

      I can’t remember off the top of my head if the e350 frame measures out the same as the f-series pickup trucks, but you may want to look into that and see what kind of skid-plate options are available and if they’ll cover your catalytic converter.

    • Wanda

      I have Ford E350 shuttle buses and I have the Catstrap on all of them. I have not had anymore problems since they tried to steal one catalytic converter from my business yard. Good luck, the Catstrap is working for me since June 2021.

  2. Jay


    You can buy the CatClamp directly from or try one of the many online auto parts stores. Although you may save a few bucks NOT buying from CatClamp direct, sometimes the manufacturer can provide support that the online shops can’t.

    Good Luck!

  3. Joy

    Right now in my neighborhood the Honda CRVs are being targeted. I have a 2010 CRV. Would the Millercat work on my car?

    • Jay

      Hi Joy.

      MillerCat has been listening and expanding their line up to include Toyota Tacomas, Toyota Tundras and Sequoias, but nothing for the Honda CRV- yet. We’re getting alot of traffic from Honda CRV owners wanting Catalytic converter protection, but looks like the best bet at this time (November 2021) for something “off the shelf” would be the CatClamp or the CatStrap.

      I’ve mentioned before that I’d like something like the MillerCat for my Honda because of the clean looks. In reality though, my CatClamp has been going on 4 trouble free years and its underneath the car where i really don’t see it.

      Hopefully, once you have ANY device installed, Catalytic Converter theft on your CRV is something you can cross off your worry list!

      Good luck!

  4. Dee

    Can I use the Cat clamp on a 2013 Hyundai Elantra? I don’t know what I would use and I’d like to get something to ease my mind!

  5. John Hibert

    Need theft cover for 96 Ford E 350 Cutoff van. 7.3,gas engine

    • Jay

      Hi John.

      Check out the reply to Jeffery about his E350 Bus, which is most likely a cutaway. Bottom line, if you’re looking for something off the shelf, check out the Cat Clamp.


Submit a Comment

Your email address will not be published. Required fields are marked *