How to Select a Catalytic Converter for Your Vehicle


When it comes to replacing your ride’s faulty catalytic converter, you have two options. You can either spend a small fortune at the dealership… or save a bundle by doing the job yourself with an aftermarket replacement. Before you rush off to the garage, remember that not all replacements are street-legal in all states — and they’re not as easy to install as a set of floor mats. If you want your at-home install to go smoothly — and not raise the eyebrows of your local smog-sniffer — you’ve come to the right place. This guide breaks down the key information to get the best aftermarket cat for your car, truck or SUV.


Magnaflow Catalytic Converters – 49 State Legal

Identify the emission system with which your vehicle came

First things first. It’s important to know what type of emissions equipment came from the factory. To do that, you can pop your hood and check for an emissions equipment sticker. These are typically to be found under the hood, or near the firewall area behind the engine in a visible area. States can either follow the federal standards set by the Environmental Protection Agency or they can adopt the stricter California Air Resources Board (CARB) regulations.

  • If your vehicle was originally sold in California, it will have emissions equipment that meets the CARB standards.
  • If your vehicle was originally sold somewhere outside California, it may or may not be equipped with CARB-acceptable equipment. It depends on whether the state follows California standards. Check that state’s DMV site for more info.


In what state is your vehicle registered?

Now that you know what type of smog-blockers came stock, it’s time to consider where your vehicle will be registered. Every state can choose to follow either the EPA’s standards or California’s standards, and your catalytic converter has to meet the standards of your state.

  • If you plan on registering your vehicle in California, you must use a catalytic converter that meets CARB standards.
  • If you live in New York, aftermarket catalytic converters must also meet CARB standards.
  • If you live in any other state, visit your DMV (digitally or physically) to find out whether they require aftermarket cats to meet EPA or CARB standards. Generally speaking, 49-state converters typically fulfill emissions requirements in these other states. However, emissions laws are constantly evolving and they could be different by the time you read this sentence.

What is CARB?

Direct-fit vs. Universal

  • Direct-fit catalytic converters are engineered to match the cat that came on your vehicle, from the diameter of the tubing to the placement of the O2 sensors. They generally bolt directly into place with no welding required, and they’re the easiest to install. However, they’re only available for a select number of vehicles.
  • If there’s not a direct-fit catalytic converter available for your vehicle, you can always go with a universal replacement. You have to measure your existing exhaust and might have to weld it into place, but they generally cost less. Just make sure it has the right sensor ports — the last thing you want to discover after it’s welded into place is that you need to bung it.


Shop Popular Catalytic Converters

Flowmaster Direct-fit Catalytic Converters – 49-State Legal


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Mike Cote
My 2015 Toyota Tacoma TRD Off Road Access Cab 4x4 offers bed space to camp in, haul my dirt bike around, and it's been done up to take on the trails. Favorite mods include my Icon coilovers to soak up the bumps. My Walker Evans 501 Legend wheels wrapped in Toyo RT tires give me the clearance from my upper control arms to fit (and they look darn good) and the over-sized tires take on rocks with plenty of traction. My Rigid Industries fog lights have kept me out of a ditch or two when night wheeling. Growing up going to car shows and helping my dad work on the family vehicles ignited my passion. My best memory was the first time I flushed the coolant. My dad forgot to tell me to keep my face out from under the drain plug. Never made that mistake again!


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