Which Catalytic Converter Protection Is Right for Your Toyota?
Toyota owners looking for catalytic converter theft protection may encounter MillerCAT Cat Shields offered through Toyota dealerships as well as independent aftermarket products such as ADD A CAT by ADD Automotive.
Seeing a shield at a Toyota dealership doesn't necessarily mean Toyota manufactured the shield. Toyota's current accessory program identifies MillerCAT as the manufacturer of its offered Cat Shield products, and Toyota states that these accessories are not designed, manufactured, evaluated, or warranted by Toyota.
That's why Toyota owners should compare the actual shield, not simply where it's sold.
ADD A CAT vs. Toyota Dealer Shield Options
| Feature | ADD A CAT | Toyota Dealer MillerCAT Option |
|---|---|---|
| Manufacturer | ADD Automotive | MillerCAT |
| Vehicle-specific | Yes | Yes |
| Material | 3/32" 5052 marine-grade aluminum | 5052 aluminum or stainless steel depending on application |
| Construction | One-piece ADD A CAT design | Varies by application |
| Security hardware | Proprietary ADD A CAT security bolts | Tamper-proof screw kit |
| Security bit/hardware | Included | Installation/security hardware included |
| Installation | Bolt-on / no drilling | Drill-less on current applications checked |
| Ventilation | Integrated louvers | Varies by application |
| Houston installation | FREE with shield purchase | Professional dealer installation available; cost varies |
| Shipping | Free nationwide | Dealer/product dependent |
| Warranty | ADD Automotive warranty | Manufacturer/dealer terms apply |
Toyota's own parts listings confirm MillerCAT aluminum shields made from 5052 aluminum with drill-less installation and tamper-proof hardware; Toyota also lists stainless-steel MillerCAT versions for certain applications. ADD Automotive currently specifies 3/32-inch 5052 marine-grade aluminum, proprietary security bolts, one-piece construction, louvers and no-drill installation for ADD A CAT.
Don't Just Ask, "Is It From the Toyota Dealer?"
Ask:
Who actually manufactures the shield?
What material is it made from?
How is it secured to my Toyota?
How many pieces does it use?
What does the warranty actually cover?
What is my total installed price?
Those questions provide a much better comparison than simply assuming the dealer option must be best.
The ADD A CAT Difference
ADD A CAT is purpose-built by ADD Automotive as a catalytic converter theft-deterrence system.
Current Toyota ADD A CAT shields feature:
✓ 3/32" 5052 Marine-Grade Aluminum
✓ One-Piece Construction
✓ Proprietary Security Bolts
✓ Security Bit Included
✓ Integrated Ventilation Louvers
✓ Vehicle-Specific Engineering
✓ Bolt-On Installation
✓ No Drilling
✓ Free Nationwide Shipping
✓ FREE Houston-Area Installation
ADD Automotive's current Toyota collection confirms these specifications and benefits.
One-Piece Construction
ADD Automotive's design philosophy is straightforward:
FEWER PIECES. FEWER CONNECTIONS. FEWER POTENTIAL ACCESS POINTS.
ADD A CAT uses a one-piece design engineered around the specific vehicle.
Rather than judging a catalytic converter shield only by the material, Toyota owners should examine the complete system:
Coverage + Construction + Fasteners + Mounting + Airflow + Fitment
Proprietary Security Hardware
A catalytic converter shield is only part of the security system.
The hardware holding it underneath your Toyota matters too.
ADD A CAT uses proprietary security bolts, with the corresponding security bit included in every hardware kit.
Toyota's current MillerCAT dealer offering also includes tamper-proof security hardware.
That's an important point because this isn't a comparison where the dealer product has ordinary bolts. Both systems take fastener security seriously.
The question becomes which complete design you prefer.
Dealer Installation vs. ADD Automotive Installation
Toyota says professional installation of its MillerCAT accessory is available through Toyota dealerships. Dealer pricing can include additional installation and dealer charges.
ADD Automotive takes a different approach for Houston-area customers:
FREE FACTORY-DIRECT INSTALLATION
Purchase an eligible ADD A CAT shield and ADD Automotive will install it in the Houston area at no additional installation cost.
Appointment required.
We design it.
We build it.
We install it.
Toyota Dealer Doesn't Necessarily Mean Toyota Manufactured
This is one of the most important facts for shoppers to understand.
Toyota's 2026 accessory portfolio lists MillerCAT Cat Shield™ for Toyota models including the 4Runner, Corolla, Highlander, Prius, RAV4, Tacoma, Tundra, Sequoia and Venza. Toyota then states that the featured accessories are not designed, manufactured, evaluated or warranted by Toyota and directs consumers to the accessory manufacturer for warranty information.
That doesn't make MillerCAT a bad product.
It simply means consumers should make an accurate comparison:
ADD A CAT by ADD Automotive
vs.
MillerCAT sold through a Toyota dealer
—not assume the comparison is ADD A CAT versus a Toyota-manufactured shield.
What About Genuine Toyota Parts?
There is another important distinction.
Toyota's parts catalog also contains certain components actually branded Toyota Genuine, including a catalytic converter protector under part number 18435-0C030. Toyota describes that particular component as a fitted protector around the catalytic-converter area and states that it carries Toyota Genuine parts coverage.
Therefore, before comparing any dealer product with ADD A CAT:
GET THE PART NUMBER.
That tells you whether you're looking at a MillerCAT Associated Accessory Product, a Toyota Genuine component, or another dealer-supplied product.
Which Should You Choose?
A Toyota dealer-sold MillerCAT shield is a legitimate catalytic converter theft-deterrence option. It offers vehicle-specific construction, tamper-resistant hardware and drill-less installation on current applications we checked.
ADD A CAT offers Toyota owners a different package centered around:
3/32" 5052 marine-grade aluminum
One-piece construction
Proprietary ADD A CAT security hardware
Integrated ventilation louvers
No-drill installation
Free nationwide shipping
Free Houston-area factory-direct installation
The better choice depends on your exact Toyota and the particular dealer shield being offered.
Compare the actual products—not just the names selling them.
Frequently Asked Questions
Does Toyota sell catalytic converter shields?
Yes. Toyota currently lists MillerCAT Cat Shields among its Associated Accessory Products for several Toyota vehicles.
Does Toyota manufacture the MillerCAT shield?
No. Toyota's current accessory brochure identifies MillerCAT and states that these accessories are not designed, manufactured, evaluated or warranted by Toyota.
Is ADD A CAT a Toyota dealer shield alternative?
Yes. ADD A CAT is an independent aftermarket catalytic converter shield manufactured by ADD Automotive for supported Toyota vehicles.
What is ADD A CAT made from?
ADD Automotive specifies 3/32-inch 5052 marine-grade aluminum.
Does ADD A CAT require drilling?
No. ADD Automotive currently specifies complete bolt-on installation without drilling.
Does a Toyota dealer-installed MillerCAT require drilling?
The Toyota-listed MillerCAT products I checked are described as completely drill-less. Always verify the specific part number for your Toyota.
Compare Before You Buy
Before purchasing catalytic converter protection from a Toyota dealership, get the:
Manufacturer • Part Number • Material • Construction • Security Hardware • Warranty • Total Installed Price
Then compare it with:
ADD A CAT by ADD Automotive
PURPOSE-BUILT CATALYTIC CONVERTER PROTECTION
ADDAUTOMOTIVE.COM
281-608-2894
ADD A CAT is an independent aftermarket product. Toyota, MillerCAT and associated model/product names are trademarks of their respective owners. ADD Automotive is not affiliated with, sponsored by, or endorsed by Toyota or MillerCAT. Competitor specifications vary by application and may change. No physical anti-theft device can guarantee that theft is impossible.
