This part’s job is basically to help your catalytic converter work more efficiently, and to protect it. It takes some of the initial work of cleaning up exhaust gases before they even get to the main catalytic converter. It handles some of the tougher stuff right at the start, reducing harmful emissions. There are actually two of these working together—hence the “double” part—so it’s a robust system for handling exhaust cleanup. It’s located pretty early in your exhaust system, right after the exhaust manifold. Think of it as a first line of defense against pollution. It works alongside your oxygen sensors to make sure everything’s running cleanly. It’s designed to reduce hydrocarbons, carbon monoxide, and nitrogen oxides—the really nasty stuff in exhaust. Well, if this thing fails, your catalytic converter has to work much harder. The converter itself is expensive to replace, so keeping this precatalyst healthy protects that bigger investment. You’ll notice if it's failing because your check engine light will probably come on, and you might even smell a rotten egg smell from the exhaust. It also helps your car pass emissions tests, of course. A failing one can cause decreased fuel economy too. We carry a good selection of these at Fixparts Online, and we can check if this one fits your specific vehicle if you'd like. Perfect fit for your vehicle: Double Precatalyst (MPN 3B0857739DFCN) comes with a 12-month warranty!

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