Catalytic converters were once hailed as a miracle invention for their ability to remove the worst parts of a vehicle’s toxic emissions and prevent the air in the cities from becoming literally unbreathable. It’s now a must-have on your car’s exhaust system and a vehicle without a working one faces the possibility of being deemed unroadworthy.

What exactly is a catalytic converter? How does it work? More importantly, how do we know when this critical system on our vehicle is malfunctioning? These are the core questions behind today’s blog.

What Is a Catalytic Converter? How Does It Work?

A catalytic converter is a device that makes up a critical part of your car’s exhaust system. It was first developed in 1973 at the Engelhard Corporation and soon came into wider use from 1975. From that year, they started to become a requirement on all cars as a way to prevent toxic emissions.

Catalytic converters use a process of reduction and oxidation reactions — also known as “redox” reactions — which reduces the most harmful elements found in car exhaust fumes down to negligible quantities. It achieves these reactions using a number of precious metals which coat a series of ceramic beads. These precious metals are the catalysts that form the first part of the catalytic converter name.

In particular, the converter removes nitrogen oxides (NO_x) by eliminating their nitrogen and nitrogen oxide molecules, leaving plain oxygen. Other harmful elements removed by the catalytic converter include hydrocarbons and carbon monoxide.

When working properly, a catalytic converter can rid your exhaust fumes of more than 90 percent of these harmful components. In the process, however, it does convert some into carbon dioxide, which has its own issues, but at least it’s not directly toxic in the same way as the other elements are.

What Are Some Common Problems With Catalytic Converters?

The catalytic converter is undoubtedly a brilliant innovation and is designed to last for at least 10 years or more, but like any other mechanical car part, it’s not without its own problems. Below are some of the common problems that can occur with catalytic converters.

First is contamination. There are a number of substances that if they find their way into the catalytic converter will wreak havoc among the catalysts that perform the redox reactions. One such contaminant is actually humble engine coolant. If it finds its way into a faulty cylinder head gasket, it can inevitably end up in the catalytic converter and cause contamination. Another bad substance is leaded gasoline, though that’s thankfully rare in the US nowadays.

Second is clogging and overheating. As you know, the many parts of your car’s engine and exhaust systems are all interconnected. When one part fails, it causes a domino effect further down the line. For instance, if your spark plugs are faulty and misfires, then it can bring excess amounts of unburned gasoline into the exhaust system, which then gets into the catalytic converter and leads to clogging and overheating. Faulty oxygen sensors can lead to the same outcome of clogs and overheating.

Third is theft. Yes, catalytic converters are under constant threat of a third menace, which is finding themselves removed from their home vehicle by criminals and assorted hoodlums. Why do these thieves target the catalytic converter? Remember that within the ugly metal housing of the catalytic converter lies a series of beads coated in precious metals. These are worth a lot to the right kind of buyer, which leads criminals to target catalytic converters for theft.

It’s not unlike those who target the railways for copper wiring/cables when copper prices are high. Sometimes metal is literally worth its weight in gold.

Bad Catalytic Converter: Symptoms

Catching problems in the catalytic converter early is important because it’s an expensive component to replace. Below are some symptoms to look out for that indicate your catalytic converter is in need of professional attention.

Your Emissions Are Up

Did you recently take an emissions test that you either failed or came very close to failing? This is a classic sign that the converter is not working as well as it should be. You may also notice additional exhaust fumes when you start or even as you’re idling or driving. No modern car should even come close to failing an emissions test with its working catalytic converter.

You See a “Check Engine” Light

Of course, the “Check Engine” light can mean many things, but it will certainly illuminate if there’s a problem with any part of the catalytic converter. If you notice the “Check Engine” light in conjunction with any of the other symptoms in this list, then you should get your car to the auto shop as soon as you can.

Your Gas Mileage Is Down

Another classic symptom of a failing or clogged catalytic converter is reduced gas mileage. When the converter isn’t working properly, it can mean the engine isn’t getting the oxygen that it needs to work most efficiently. When this happens, the engine has to work harder to compensate, and that means more fuel is consumed.

You’re Having Trouble Starting

If your catalytic converter has become clogged up, which in turn increases exhaust pressure on your engine. That additional pressure will cause your engine to stall out before it can even start and get running. As with the “Check Engine” light, there are multiple reasons for an engine not starting. For instance, you might have a depleted battery or faulty alternator. However, a clogged catalytic converter is another possibility.

You’re Experiencing Sluggish Acceleration

Finally, when the catalytic converter is not working at full capacity, it will directly impact your car’s acceleration. If you notice that you’re flooring the gas pedal but going nowhere very fast, then it could be a clogged converter that’s your problem.

What Is The Typical Cost of a Catalytic Converter Replacement?

To repair a catalytic converter will set you back somewhere between $945 and $2,475 including all parts and labor. To replace the unit itself will cost somewhere in the region of $2,250. As we mentioned further above, it’s an expensive component, made even more so by the precious metals housed within it.

Conclusion: Bad Catalytic Converter – What to Do Next

The catalytic converter is a very technical and advanced piece of equipment on your car. It may date back to the 1970s, but it involves some pretty intricate components and processes and requires a careful balance within its mechanics to work properly.

This being the case, the best course of action when you experience the symptoms that we covered in today’s blog is to take the car directly to a garage. It may be an expensive fix, but the repair will almost always be cheaper than having to get it replaced when you neglect a small problem that then turns into a major catastrophe.

Your car can’t be roadworthy without the catalytic converter, it’s as simple as that.

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