We covered the difference in EPA, CARB-compliant, and CARB-exempt converters, but as a short review:
- EPA cats meet federal emissions standards set by the Environmental Protection Agency. They use fewer precious metals than CARB-compliant cats, and don't meet strict CARB rules, but still clean exhaust gases and meet federal Clean Air Act requirements.
- A CARB-compliant catalytic converter is built to go beyond EPA standards and meets the strict emissions standards set by the California Air Resources Board (CARB).
- CARB-exempt cats don’t have to meet CARB’s strict standards because they’ve been granted a special exemption, granted via an Executive Order (EO). They don't quite meet CARB’s emissions standards but are still approved for use in CARB states under certain conditions.
Okay, so how do you know if you need a CARB-compliant or CARB-exempt catalytic converter? It’s all about your vehicle and where you’re driving it. Here’s a simple checklist to keep your ride on track.
How To Tell Which Catalytic Converter You Need
Check Your Vehicle’s Emissions Certification: Look for the Vehicle Emissions Control Information (VECI) label under the hood, on the strut tower, radiator support, or hood itself. It’ll say if your car is:
- CARB-certified (If it says 'CARB,' 'ARB,' or terms like LEV, ULEV, or SULEV, you’ve got a CARB vehicle.)
- EPA-certified
- 50-state certified (meets both)
Pro Tip: If the label’s missing, punch your VIN into a dealer’s database or use a VIN decoder to confirm your emissions setup.
Know Your State’s Rules:
- In CARB states, you need a CARB-compliant cat for most street-legal vehicles, especially newer model). Check the model year requirements for your state.
- In non-CARB states, you can usually use an EPA-compliant cat (sometimes called '49-state' cats), which cost slightly less and are legal for federal emissions vehicles.
But if your car is CARB-certified, you might still need a CARB-compliant cat, even in a non-CARB state, to avoid a check engine light or OBD-II codes. Use CARB-exempt cats only if you’ve got an EO number matching your specific vehicle and use case (e.g., off-road or racing). Check CARB’s database or your part’s documentation.
Match the Cat to Your Build: For daily drivers or stock setups, go CARB-compliant to stay legal and keep your emissions tight. For performance builds or track cars, a CARB-exempt cat might work if it’s got an EO for your specific setup. You'll need to dig into the regulations.
Watch for OBD-II Compatibility: Modern cars use OBD-II systems to monitor cat performance. A basic EPA universal-fit cat on a CARB vehicle might trigger a check engine light, even if it fits physically. CARB-compliant direct-fit cats are designed to keep your OBD-II happy with higher precious metal loads and better washcoats.
Why Having The Right Catalytic Converter Matters
Picking the wrong cat can lead to some serious headaches. In CARB states, installing a non-compliant cat is illegal and they can slap you with fines. Even in non-CARB states, using an EPA cat on a CARB-certified vehicle might cause an error code, meaning your cat’s not cleaning emissions well enough, and you’ll fail a smog test.
Plus, CARB-compliant cats tend to last longer, thanks to more platinum and rhodium - they’re a solid investment for high-mileage rides. CARB-exempt cats, on the other hand, are great for squeezing extra performance out of your build but require careful research to ensure they’re legal for your use.
Catalytic Converter Tips From The Pros
Here are a few insider tips to keep your catalytic converter game strong:
- Shop With Trusted Suppliers: Go for reputable sources with a history. At CatalyticConverter.net we've been selling converters, exhausts, mufflers, and manifold components and accessories since 1996.
- Check the EO Number: For added security, you can always verify the EO number on CARB’s aftermarket converter database. It’s your ticket to passing a smog check.
- Decide Your Spend: A basic, low-cost cat will have less catalytic material - which is fine for certain applications or short-term needs. However, if you need more, spend more and get the peace of mind you seek.
- Consider A Pro Install: In some states, only certified technicians can legally install cats. Make sure your shop knows the rules to avoid a costly redo.
- Diagnose First: An error code doesn’t always mean a bad cat. Remember that most modern converters are designed to last the life of the vehicle. Check O2 sensors, exhaust leaks, or engine issues first to avoid swapping a good cat.
High-Quality Catalytic Converters From CatalyticConverter.net
CatalyticConverter.net has been a trusted source for converters, exhausts, mufflers, and manifold components and accessories since 1996. Whether you're building a high-performance track machine or keeping your vehicle street-legal, we can help you find the cat you need. Shop our huge selection, backed by fast shipping, expert support, and free delivery on orders over $75 within the continental US.
Not sure which converter fits your performance goals or emissions requirements? Reach out to our team - we’re here to help you find the perfect fit.