Every time you drive, your vehicle’s catalytic converter is hard at work. This ingenious component helps produce cleaner emissions by turning toxic exhaust gasses into less harmful ones. How it accomplishes this feat certainly isn’t magic: It just uses basic scientific principles. Understanding your converter is important in keeping your vehicle is good running condition. This quick guide explains how catalytic converters work, how to tell if there’s a problem and what you can expect to pay for replacements.

Why You Need a Catalytic Converter?

Starting with the 1975 model year, every vehicle in the United States must have a catalytic converter. It’s one of the ways that federal and state governments fought pollution throughout the 20th century. Before converters were a thing, vehicles used leaded gas and put out dangerous pollutants such as carbon monoxide. And as more cars and trucks hit the roadways, major U.S. cities like New York and Los Angeles developed serious smog problems.

Catalytic converters use a simple structure to convert harmful emissions. Your converter includes a rectangular metal box with two ports – one entering the unit and another exiting it. Exhaust enters the converter from your engine and passes through a metal honeycomb covered in catalysts. A reduction catalyst breaks down nitrogen oxides into nitrogen and oxygen. Meanwhile, oxidative catalysts convert hydrocarbons and carbon monoxide into CO2. Those converted gasses exit the unit and leave your vehicle through its tailpipe.

You may wonder, “How much is a catalytic converter?” Many catalytic converters are direct fitment parts, so their costs can vary. Basic converters start at around $180, but they can price out more depending on your vehicle’s make and model. If you want a high-end performance converter, be prepared to pay at least $1,000 or more.

How To Tell Your Catalytic Converter Has Gone Bad

Your converter is durable and dependable. Most versions last at least a decade or more. But that doesn’t mean it’s impervious to damage or faults. Some units wear out over time, but others develop clogs from leaking engine coolant. Leaded gas is rare, but accidentally putting it in your tank can permanently ruin your converter. Some converters can also overheat from misfiring spark plugs, bad oxygen sensors or leaking exhaust valves. There’s also theft to worry about: Converters use precious metals such as palladium, platinum and rhodium, so their scrap metals can command high prices.

Fortunately, spotting a catalytic converter problem doesn’t take much guesswork. Watch out for some common symptoms:

  • Slow or reduced engine performance
  • Sluggish acceleration
  • Rotten egg exhaust smells
  • Black or dark gray exhaust smoke
  • Too much heat under the vehicle

How To Replace Your Converter

To solve your converter problem, you need to know what’s wrong. Some clogged converters can be fixed by unclogging them, but you may need to eventually replace them. Thankfully, it’s easy to find a new converter. Choose a trustworthy auto parts dealer with a large selection, great customer service and favorable exchange/return policies. Most should have make/model/year search options, but some offer VIN number search tools. Either one can help narrow down to units that properly fit your vehicle.