When your vehicle fails an emissions test, a failed or damaged catalytic converter is often the problem. Catalytic converters are designed to reduce harmful gases before they exit the tailpipe, but like any part, they wear out over time.
A replacement catalytic converter can help your car pass emissions testing - but only if you install it correctly and use the right type for your state.
What Is Emissions Testing?
Emissions testing is a state-mandated inspection that measures the pollutants leaving your vehicle’s exhaust. The main goal is to reduce harmful emissions such as:
- Carbon monoxide (CO)
- Hydrocarbons (HC)
- Nitrogen oxides (NOx)
If your catalytic converter is old, clogged, or damaged, your vehicle may fail testing. Installing a new converter often restores compliance.
Types Of Replacement Catalytic Converters
Not all catalytic converters are the same. The one you need depends largely on your state’s requirements:
| Type | Certification | Where They’re Legal |
| CARB-Compliant | Meets California Air Resources Board (CARB) standards | California & states that adopt CARB rules (e.g., NY, CO) |
| EPA-Compliant | Meets Environmental Protection Agency (EPA) standards | 49-state legal (except CARB states) |
| CARB Exempt/Direct Fit | Designed for specific vehicles | Depends on state law |
If you live in a CARB state, you must install a CARB-approved catalytic converter. Using a non-CARB converter will result in an automatic fail, even if emissions look clean. For a detailed look into CARB-compliant catalytic converters, read about it here.
Why A New Catalytic Converter Might Still Fail
Think of the catalytic converter as part of a larger emissions system. If other components aren’t functioning correctly, the system as a whole won’t pass.Even a brand-new converter can fail emissions if certain conditions aren’t met, such as:
- Installing the wrong type: Using an EPA converter in a CARB state.
- Using a non-vehicle-specific cat: Universal cats that don’t match your make/model.
- Incorrect installation: Exhaust leaks, poor welds, or sensors left loose will all result in emissions test failures.
- Other Vehicle Issues: A failing O2 sensor, engine misfires, excessive oil burning and other engine issues can overload and damage the new cat.
If you suspect your cat (even a new cat) is not working correctly, check out this article on the top symptoms of a failing catalytic converter.
Replacement Cats From CatalyticConverter.net
Driving with a damaged catalytic converter is not safe for you or your vehicle, and it’s also harmful to the environment. It will also mean that your vehicle will fail any emissions testing until it is replaced.
| Catalytic Converters | Exhaust Components |
| Direct-Fit Catalytic Converters | Exhaust Manifolds |
| Universal-Fit Catalytic Converters | Exhaust Pipes and Mufflers |
We're your one-stop shop for all cat requirements. We have been selling online since 1996, offering thousands of approved parts that meet EPA and CARB standards, and we provide free shipping on orders of $75+ to the continental US.
We make catalytic converter replacement easy, and we also specialize in exhausts, mufflers, and manifolds. Contact us if you have questions about fitment, and order your high-quality replacement catalytic convert