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Miller CAT

Miller CAT makes Cat Shield catalytic converter protection and MCX skid plates, both built to defend your vehicle's underbody, one against theft, the other against trail damage, using 304 stainless steel construction.

At Redline360 we carry Miller CAT's full lineup including Cat Shield catalytic converter protection and MCX engine, gas tank, and trailing arm skid plates for Toyota, Honda, Ford, and Nissan vehicles, including the Tacoma, 4Runner, Prius, and Sequoia. All Miller CAT products are 100% CARB compliant and manufactured domestically. Every product ships fast from our US Distribution Centers, and we can help you confirm the right fit for your specific vehicle.

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Miller CAT Questions Answered

A Cat Shield is purpose-built to protect specifically against catalytic converter theft, bolting closely around the converter itself. An MCX skid plate provides broader underbody protection for the engine, transmission, gas tank, or trailing arms against impacts from rocks, stumps, and trail obstacles during off-road driving. Many owners run both together for complete underbody protection.
Miller CAT's MCX skid plates use 304 stainless steel rather than the powdercoated mild steel or aluminum used by most competing brands. Stainless steel resists denting and returns closer to its original shape after an impact compared to aluminum, which tends to crumple and hold a dent, while also resisting the corrosion that can affect mild steel over time.
No, Miller CAT MCX skid plates are engineered with service windows that allow direct access to the oil filter and oil drain plug, so routine oil changes don't require removing the skid plate. Some vehicles may require the skid plate to be removed for less frequent transmission fluid changes, so check your specific service schedule.
RCI and similar off-road skid plate brands typically use aluminum or mild steel construction, while Miller CAT uses 304 stainless steel, which generally offers better impact resilience and corrosion resistance at a comparable weight. The right choice often comes down to whether you prioritize stainless steel's durability or the lighter weight some aluminum options provide.
A catalytic converter shield is a steel or stainless steel plate that bolts around the catalytic converter, creating a physical barrier that makes it significantly harder and more time-consuming for a thief to cut the converter out, deterring theft without modifying the exhaust itself.
Catalytic converters contain small amounts of platinum, palladium, and rhodium, precious metals that can be sold to scrap buyers for a meaningful payout. Hybrid vehicles like the Prius and trucks with higher ground clearance like the Tacoma and 4Runner are particularly targeted since their converters contain more precious metal and are easier to access from underneath.
CARB stands for the California Air Resources Board, which sets emissions standards that any part installed near or around the exhaust system must meet to be legal for use in California and other states that follow CARB regulations. Miller CAT's products are 100% CARB compliant, meaning they don't interfere with emissions equipment and won't cause issues during a smog inspection in states with strict emissions enforcement.
Under the federal Magnuson-Moss Warranty Act, a manufacturer generally cannot void your entire vehicle warranty simply for installing an aftermarket protective device like a Cat Shield or skid plate, since neither modifies the exhaust, emissions, or drivetrain system itself. This is general information only, not legal advice, so consult your vehicle's warranty documentation or a qualified attorney for guidance specific to your situation.
Comprehensive auto insurance typically covers catalytic converter theft, though you'll usually still pay your deductible, and repeated claims can affect your premium. Coverage details vary by policy and provider, so confirm your specific coverage with your insurance company, and consider a Cat Shield as a way to reduce your risk of needing to file a claim at all.

Do You Need a Cat Shield, a Skid Plate, or Both?

High Theft Risk: Cat Shield

If you drive a Prius, Tacoma, 4Runner, or another vehicle on the commonly targeted list for converter theft, a Cat Shield is one of the most cost-effective ways to reduce your risk, regardless of whether you drive off-road. Catalytic converter theft disproportionately targets a specific set of vehicles based on ground clearance and converter material content.

Off-Road Driving: MCX Skid Plate

If you regularly drive forest roads, dirt tracks, river crossings, or rough terrain, an MCX skid plate protects your engine, gas tank, or trailing arms from impact damage that a Cat Shield isn't designed to prevent. The available gas tank and trailing arm skid plates are worth considering as separate upgrades from the engine skid plate, since each protects a different vulnerable component.

Both: Complete Underbody Protection

Many owners, particularly Tacoma and 4Runner drivers who both park in high-theft urban areas and drive off-road on weekends, run a Cat Shield together with an MCX engine skid plate for complete underbody protection against both theft and trail damage.