catalytic converter

How long can you drive with a bad catalytic converter? I don’t know about you, but I take my car for granted. Public transportation by me isn’t great, so I need that car to get around town and live my life. However, as cars age, parts can wear out and need replacing. You know you will need new brakes or new tires. But, have you ever thought about the catalytic converter?

Maybe you’ve never thought about it, or don’t even know what it is.

If you know what a catalytic converter is and yours is broken, or suspect it is, you might be wondering how long can you drive with a bad catalytic converter?

How Long Can You Drive With A Bad Catalytic Converter?

Technically, you can drive with a bad catalytic converter as long as you want.

Your car or RV can and will function without a catalytic converter. In fact, vehicles didn’t even have catalytic converters until 1975. Which means an older model car may not have one.

However, if your catalytic converter isn’t working, you should probably replace it ASAP!


While You Can, You Shouldn’t Drive Without A Catalytic Converter

Asking “How long can you drive with a bad catalytic converter,” isn’t really the right question. You should ask “Will anything bad happen if you keep driving with a bad catalytic converter.”

You won’t ruin your car or RV.

In fact, some car enthusiasts insist your vehicle will perform better without the catalytic converter. Whether or not that’s the case, there are still several reasons why you should replace a broken one.

It’s terrible for the environment

The catalytic converter helps protect the environment. Without it, every time you drive you’re releasing harmful pollution into the air.

If you’re in a campground setting, this could be detrimental to forming good neighborly relations with the folks camped next to you. Also, while driving, the bad catalytic converter could be releasing harmful gas into the passenger areas of your RV.

It will eventually burn through

How long can you drive with a bad catalytic converter?

As long as you want.

But, if you keep driving with a broken catalytic converter, over time, you’ll burn it out. That’s not bad, but you will notice a bit of smoke every time you drive.

And that’s kind of scary.

Your car or RV won’t perform

A malfunctioning catalytic converter will cause your vehicle to function less efficiently. Again, that doesn’t prevent your vehicle from driving, but you may not like it when you hit the gas and nothing seems to happen.

It’s mandatory

Since the answer to the question “How long can you drive with a bad catalytic converter” is “as long as you want,” you may be thinking that if yours is bad, you can skip the replacement. After all, it’s expensive to replace, and it’s not hurting the car.

Well, you’d be wrong.

While laws vary by state, the EPA has a strict set of guidelines regarding catalytic converters in vehicles. That includes Recreational Vehicles (RVs).

The bottom line is:

It doesn’t matter how long you think can you drive with a bad catalytic converter. Because when you ask “how long can you drive with a bad catalytic converter,” the answer is “not that long.”

If you’re caught driving a vehicle without a catalytic converter, you could be subject to fines and also be unable to drive your car or RV until you replace the catalytic converter.

What Does The Catalytic Converter Do?

You get in your vehicle, turn the key, and ta-da! Your vehicle starts, and you’re on your way.

While you’ve probably never thought about it, you know that some reactions need to happen. Like, a combustion reaction to convert the gas in the tank into fuel for the engine.

Without getting into all of the details, you know that when a combustion reaction occurs, your vehicle moves. And, you probably also know that when the said reaction happens you release pollution in the air — things like carbon monoxide and hydrocarbons.

While pollution is terrible, it is currently an unfortunate byproduct of driving. Cars still need gas to function, at least for a little while longer. And that’s where your catalytic converter comes in.

Inside your catalytic converter, there’s a catalyst. It’s made up of precious metals (platinum, palladium, and rhodium) that coat a honeycomb structure attached to the exhaust pipe. The metals are the catalyst.

When you turn the key, you start the combustion reaction that creates pollution. The pollution heads out your exhaust. But first, it passes through the catalytic converter. When the exhaust stream hits the honeycomb, the catalyst converts the pollutants into something less harmful.

They’ve Come A Long Way

Catalytic converters have a bad reputation.

It’s true that early versions of catalytic converters were not remarkable. Some of the first catalytic converters decreased engine performance causing the car to have less horsepower (meaning, they didn’t accelerate when you wanted).

There were also some reports of tall grass catching fire due to the catalytic converters. This happened because the car or RV was parked in a yard or field, the converter was still hot and caused the grass to catch fire.

However, today’s catalytic converters don’t have that problem. They are safe and don’t affect engine performance.

And, they help protect the environment by converting those harmful exhaust fumes.

Signs You Need A New Catalytic Converter

The catalytic converter should last the life of your vehicle. However, like almost any other part of your vehicle, over time, your catalytic converter can fail.

A clog in the honeycomb is usually the cause.

You can’t check your catalytic converter like you can check your oil. However, there are some signs and symptoms that will alert you that you may need to replace your catalytic converter.

Poor Engine Performance

Maybe the engine doesn’t seem as zippy as it used to. Or, it seems like you step on the accelerator and nothing happens for a few seconds.

That generally has nothing to do with your vehicle’s age. Sluggish engine performance may be a sign that you need to replace your catalytic converter.

If your catalytic converter is clogged, the exhaust can’t leave the system as efficiently. This could lead to problems with your motor since the system won’t be able to achieve the right mix of oxygen and exhaust.

And, if the catalytic converter is damaged, your engine may not be burning the fuel as efficiently as it could.

This could mean worse gas mileage for you.

Rattling Noises

You’re driving along and here’s a persistent rattling noise that’s making you nuts!

There’s nothing loose in the back seat, the trunk, or the camper area.

So, what is making that racket?

It could be the catalytic converter. If the honeycomb structure is damaged, it can come loose from the exhaust system. When that happens, you’ll hear a rattling noise.

If you can’t locate the source of the sound but still hear a rattling noise, have your system checked.

It Looks And Smells Bad

A properly functioning catalytic converter will turn the exhaust into hydrogen sulfide — an odorless gas. When the catalytic converter doesn’t work, this transformation can’t happen, and you might get a build-up of unburned fuel in the exhaust system, which smells like rotten eggs.


Your engine can still perform well in the early stages of the catalytic system is failing. If you notice that a rotten egg smell or that the vehicle is spewing black exhaust, it’s time to get the catalytic converter checked.

Sour smelling exhaust fumes can be especially problematic in shared environments such as campgrounds and RV parks.

Failed Emissions Test

While there are plenty of reasons to fail an emissions test, a broken catalytic converter could be the culprit. Emissions tests make sure your vehicle isn’t polluting the environment.

The technician at the testing site can’t tell you why your vehicle failed, only that it did. So, if your vehicle fails the emissions test, the first thing you should check is your catalytic converter.

The Check Engine Light Is On

If the check engine light comes on, it could be due to a myriad of reasons. However, a malfunctioning catalytic converter may be the cause.

The catalytic converter monitors the gas to oxygen ratio in the exhaust system. If the system is unable to maintain the correct oxygen to exhaust ratio the check engine light should come on to alert you that there is a problem.

Now You Know How Long Can You Drive With a Bad Catalytic Converter: Hit The Road!

Now we’ve answered the “how long can you drive with a bad catalytic converter” question. And while the answer is “forever, if you want,” hopefully you know why that’s probably not the best idea.

In fact, the answer to “How long can you drive with a bad catalytic converter?” should really be “Until you can get it fixed.”

You can take yours to the shop to have them replace the catalytic converter. Or, if you’re into the DIY game, you can replace it yourself. Just make sure you get the right one!

Like a lot of replacement parts for your vehicle, catalytic converters are not one size fits all.

Catalytic converters are more efficient and better than ever. And, the odds are pretty good that your catalytic converter will last the life of your vehicle. But, be on the lookout for the signs and symptoms of a bad catalytic converter, just in case.

Have you ever had to have your catalytic converter replaced? If so, tell us about it in the comments.