Cat Security vs. MILLERCAT Speedway Showdown: Cat Shield Rivalry

The Battle of Catalytic Converter Shields: Which Product Wins in 2023?

Catalytic converter theft is on the rise in the United States, and police are struggling to keep up with the trend. These parts are highly valuable, containing precious metals like platinum, palladium, and rhodium. These metals can be sold for a high price on the black market, so criminals are willing to take the risk of stealing them.

There are a few reasons why catalytic converter theft is becoming more common. One is that the prices of these metals have been rising steadily. Another reason is that the parts are easy to remove, and they can be sold quickly for a fast profit. This means that thieves can make a lot of money in a short amount of time, all at your expense.

But there are a few things that you can do to protect your catalytic converter. One is to park in a well-lit area. This will make it more difficult for thieves to steal the part without being seen. Another option is to install a security device on your car that will make it more difficult for thieves to steal the catalytic converter.

In this guide, we pit Cat Security vs MILLERCAT in a battle to find the BEST catalytic converter shield on the market.

Kick back and dive in as we evaluate two of the industry’s leading competitors and the most effective catalytic converter theft prevention devices available in 2023.

MILLERCAT Cat Shield – The Ultimate In Catalytic Converter Anti-Theft Protection

Features Overview 

  • Featuring Cat Shield™ trademarked technology 

  • Battle-tested design for ultimate protection and peace of mind 

  • Superior engineering and build quality 

  • Easy installation means lower install costs (no welding necessary)

  • Available in high-grade 5052 aluminum or 304 stainless steel 

  • Tamper Proof Screw Kit or MILLERCAT Custom Screw Kit

  • Corrosion-resistant 

  • Integrated heat extraction holes allow for proper ventilation 

  • 90-day manufacturer’s warranty 

  • Proudly USA-Made right in California 

  • Compatible with a broad range of makes and models 

  • Complete kits with everything needed: Cat Shield, installation hardware, deadbolt, tamper-proof screw kit, Cat Shield Protected sticker, and detailed installation guide 

MILLERCAT Cat Shield Overview 

installed Catalytic Converter Shield Anti-Theft for Toyota Prius Gen 2

The MILLERCAT Cat Shield is manufactured by none other than the MILLERCAT Corporation, a company dedicated to (among other things) protecting vehicles from catalytic converter theft.

Known for staying on the cutting edge of catalytic converter manufacturing and technology, MILLERCAT’s Cat Shield™ lives up to the company’s well-earned reputation.

The Cat Shield represents the next generation in catalytic theft deterrence. Criminals are getting smarter, but so is MILLERCAT. Its GEN 2 models take protection to a whole new level, making your vehicle an unrealistic target for ‘would-be’ crooks.

Build Quality – 5/5

Cat Shields are built to the highest standard of quality and integrity, utilizing the customer’s choice of premium-grade 5052 aluminum or 304 stainless steel. Utilizing the industry’s best manufacturing practices, each piece is machined right here in the USA, going through a rigorous quality assurance process to ensure optimal performance and longevity.

Engineering and Design 5/5

With a reputation for remaining on the cutting edge of catalytic converter technology and innovation, MILLERCAT does not disappoint in the engineering and design category. Each shield is artfully and meticulously crafted to provide an optimal fit with each make and model of vehicle served. Utilizing innovative styling, MILLERCAT has improved upon its V1 designs, learning from how criminals are attempting to thwart similar devices and upgrading the styling to make their V2 Cat Shields near impenetrable to thieves.

Theft Prevention 5/5 

Where the MILLERCAT Cat Converter Shield shines is in what it was created to do: protect catalytic converters from theft.

First off, the build quality is sturdy, tailored for each make/model of vehicle, and engineered to make removal incredibly difficult. Its innovative style is such that criminals are unable to get any type of leverage for prying, and its solid stainless steel or premium-grade aluminum body makes it a beast to try and cut through. 

Even if criminals manage to make a cut, this thing still isn’t going anywhere. Utilizing tamper-proof screws or the optional MILLERCAT custom screw set, nothing short of a blowtorch, power tools, and an hour-plus of hard labor is getting this bad boy off of the vehicle.

Compatibility 3.8/5 (Need More Makes and Models)

MILLERCAT specializes in making make/model-specific cat shields to fit a wide range of vehicles. They currently offer cat shields for Honda, Toyota, Ford, and Lexus among others, covering 10+ of the most commonly burglarized makes and models.

Cost/Value 4/5

Prices range around $140-$290 depending on the specific make and model of your vehicle. Considering the build quality, engineering, warranty, and protection offered, we find that these prices are highly competitive within the industry and offer a lot of value.

installed Honda Accord 2.4L Anti-Theft Cat Shield

MILLERCAT Cat Shield Summary / Recap:


  • High-quality, durable build 

  • Available in premium 5052 aluminum or 304 stainless steel 

  • Innovative engineering to thwart advanced criminal tactics 

  • Simple installation 

  • Tamper-proof screws make disassembly by a thief nearly impossible 

  • Corrosion-resistant body and anchors 

  • Optimal thermal ventilation through integrated heat extraction holes 

  • Zinc-coated rivet nuts separate metal from touching metal to protect against Galvanic corrosion 

  • High value at competitive prices that won’t break the bank

  • Make/model specific products for unmatched fit and superior protection 


  • Not compatible with as many makes and models 

Cat Security Cat Shield 

Cat Security Cat Shield Overview 

Cat Security Cat Shield (by Cat Security) is one of the popular catalytic converter protection shields on the market. But is it the best? Let’s take a closer look at this aluminum plate shield to see if it stands up to the test that matters most.

Build Quality – 3.9/5

Visually, Cat Security looks pretty good. They have nice laser etching of their logo on the plate, and the build is made from quality aluminum. We found the product to be sturdy but wished it came with a stainless steel option. Aluminum is great for reducing weight, but also less durable and easier to pry/cut through if criminals have their way.

Engineering and Design – 3.7/5

We found that the overall design fits well on tested vehicles, so no qualms there. However, one aspect of this shield has us scratching our heads a bit. They use rivets instead of tamper-proof screws. Rivets, as you may or may not know, can be drilled out much easier than the screw kits used in the MILLERCAT Shield. Rivets also make it more difficult to remove for legitimate purposes without damaging the unit and requiring a replacement. For those reasons, we’re shaving off a couple of points here.

Theft Prevention – 3.9/5

Cat Security gets the job done, but we’ve seen better. A couple of years ago we would have given the Cat Security Shield a higher rating in the theft protection category. But as criminals have gotten more desperate, largely driven by post-pandemic socioeconomic factors, these thieves are stepping up their game. No longer is a simple aluminum plate (yeah we’re looking at you Cat Security) enough to thwart a dedicated thief looking to score. Criminals have evolved, and so should catalytic converter shields. 

Compatibility – 4/5

As far as compatibility goes, Cat Security has custom cat shields for each make and model it supports. Speaking of makes and models, Cat Security shines in this category, offering a wide range of protective shields for Honda, Toyota, Chevy, and Nissan.


Prices range quite a bit depending on the make and model in question, going as low as $135 up to $600+ on the higher end. Overall the average price for shields is higher than MILLERCAT by a good deal.

Cat Security Shield Summary / Recap:


  • Make/model specific products for a better fit and improved security

  • Lightweight aluminum build 

  • Corrosion-resistant 

  • Provides moderate protection to thwart anyone looking for an ‘easy target’

  • Good overall build quality 


  • Above-average prices for most makes and models

  • Aluminum is less durable and easier for thieves to pry and cut through 

  • Design is pretty basic and hasn’t evolved to keep up with criminal tactics 

  • Additional protection requires an ‘upsell’ called the ‘Ultimate Protection Upgrade)

  • Once installed, no future upgrades can be added

  • DAMAGE to your vehicle – this model requires PERMANENTLY drilling into the vehicle’s frame to install the screws. 

  • GALVANIC CORROSION – despite the aluminum body’s resistance to corrosion, the touching of two dissimilar metals where the screws meet the frame will cause corrosion over time.

  • If a thief messes with the Cat Security shield, you’ll need to tear off the whole shield to fix/repair

  • Use of rivets invites thieves to drill through them, while also making it difficult to remove the plate for legitimate purposes 

The Bottom Line In Our Showdown Between MILLERCAT And Cat Security

Catalytic converter theft is a serious problem that is only getting worse. Police departments are struggling to keep up with the trend, and drivers are at risk of having their car parts stolen. 

Although any form of cat protection is better than nothing, the overall value of Cat Security products could be better. We appreciated the broader range of supported vehicles but found the design to be lacking in performance, and the aluminum build might not hold up as well over time. We also dislike how the plate is attached and anchored, causing concerns about corrosion and permanent damage to our vehicle, not to mention the challenges of replacing or fixing the plate if damaged.

That said, our number one choice for catalytic converter protection is the MILLERCAT Cat Shield, featuring an innovative design, strong durable build, anti-corrosion technology, and an affordable price tag that won’t break the bank.