Can You Drive Without a Catalytic Converter?

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The catalytic converter is tougher than most parts found in your car. That’s because it needs that toughness to withstand high operating temperatures. But it can still break down or fail due to rust, impact damage, or engine performance problems. 

If the converter breaks down while you’re on the road, can you keep driving your car? Is it safe to drive without a cat? How long can you drive before you have to replace it?

Let’s answer some of these questions. 

image of a catalytic converter of a modern car
Technically, you can still drive without a catalytic converter.

Driving with a Bad Catalytic Converter: Is it Possible?

Technically, yes. Older cars ran just fine before catalytic converters became commonplace in the 1970s. So, if your question is whether your car will run without one, then it most certainly will. But the other question you should be asking is—should you risk it? 

First, what you need to know is that tampering with the catalytic converter in any way is illegal. You cannot remove or disable this component, and doing so could cost you several thousand dollars in fines. This is especially true in states like California, which has pretty strict laws regarding vehicle emissions. 

Another problem is that removing the catalytic converter from a modern car will trigger the Check Engine Light. Also, you will obviously fail your emissions test and will be unable to get your registration renewed.

What about a situation where the converter is intact but not working properly? Well, that’s a different story. If the converter is clogged or collapsed, your car may lack power and stall, making it nearly impossible to continue driving.

On the other hand, if the converter is simply suffering from a decline in efficiency, you can continue driving without having to worry about your car breaking down. 

How Long Can You Drive Without a Catalytic Converter?

If your catalytic converter has only been removed, disabled, or stolen (yes, it can happen) without resulting damage to any of the other neighboring components, you should be able to drive your car indefinitely. However, again, this is illegal and in the likelihood that you get caught, you could be fined.

Keep in mind, again, that a missing converter and a failed converter are two different things. In either scenario, you’ll want to replace the converter as soon as possible. But with a faulty converter, this means increased tailpipe emissions, which is bad for the environment. And if the converter has come apart internally, it can cause engine performance problems, as well as potential damage to other parts of your car. 

Is it Safe to Drive With a Bad Catalytic Converter?

As previously mentioned, you can drive just fine without a catalytic converter. It’s technically completely safe, although illegal and not great for the environment. 

But the question is whether it’s safe to drive if the cat is broken or breaking down—in which case, the answer is, not necessarily. It may be okay for a while, but again, driving with a bad catalytic converter can cause engine issues and possible damage to other components, so it’s best to replace it as soon as you can.

What is a Catalytic Converter?

The catalytic converter is an emission control device found in the exhaust system. First introduced in the 1970s, the catalytic converter quickly became standard issue equipment on most vehicles.  

Today, federal and state laws require its presence on nearly all vehicles. As previously mentioned, it’s illegal to remove, modify, or deliberately damage the converter for whatever reason.

close up shot of a catalytic converter
A catalytic converter transforms pollutants into harmless water and carbon dioxide.

What Does a Catalytic Converter Do?

A three-way catalytic converter transforms three pollutants—oxides of nitrogen, hydrocarbons and carbon monoxide—into harmless water and carbon dioxide.

The device uses precious metals to trigger chemical reactions that change the toxic gases into safer substances. 

Symptoms of a Bad or Failing Catalytic Converter

There are warning signs that your vehicle’s catalytic converter has failed or is starting to fail. They include:

In most cases, the only sign of a failed converter will be an illuminated Check Engine Light. But in instances where the converter becomes clogged or restricted, issues such as lack of acceleration, stalling, and hard starting may result. 

To summarize, it’s possible but illegal and potentially unsafe to drive a car with a missing or bad catalytic converter. If you must operate your vehicle before you can afford a replacement cat, try to keep your trips brief and drive to nearby locations. 

Be ready to top the fuel tank up more often and pay attention to the heat produced by the cat and engine to minimize the risk of fire.

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Staff Writers

In the Garage with CarParts.com is an online blog dedicated to bringing DIYers and devoted car enthusiasts up to date with topical automotive news and lifestyle content. Our writers live and breathe automotive, taking the guess work out of car repairs with how-to content that helps owners get back on the road and keep driving.

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