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Can You Drive With A Bad Catalytic Converter?

Can You Drive With A Bad Catalytic Converter?

When you are driving your car, it’s vital that all its parts work as they should, especially the catalytic converter. 

However, should your catalytic converter experience problems, can you still drive your vehicle? Here’s what you should keep in mind.

While you can technically still drive your vehicle when it has a bad catalytic converter, you are not legally allowed to drive it in most states.  Positioned between your vehicle’s engine and muffler, the catalytic converter plays a vital role in keeping your vehicle’s emissions as low as possible. 

Remember, more and more states have stricter emissions standards for vehicles!

When your catalytic converter starts to go bad, this means the emissions from your car’s exhaust system are at a level that is higher than allowed by your state. 

As a result, your car will not pass a vehicle inspection, meaning you’ll get a reject sticker on your vehicle and not be allowed to drive it legally until your catalytic converter is repaired or replaced.

While your vehicle’s emissions may be out of line with your state’s standards, the silver lining in this is that driving a vehicle that has a bad catalytic converter is not considered to be dangerous. 

In many situations, a catalytic converter may be malfunctioning due to part of it being plugged with various types of debris. 

If this is the case, the repair is often relatively simple and inexpensive. 

However, driving with a bad catalytic converter may impact your vehicle’s fuel mileage in a negative way. Since your exhaust system won’t be at its peak efficiency, this will mean your engine will be working harder than normal. 

When this occurs, your vehicle’s fuel efficiency may suffer, although it probably won’t be a major decline unless you choose to drive around for months and months with a bad catalytic converter.

What Happens if You Drive a Car with a Bad Catalytic Converter?

When your car starts to have a catalytic converter that is going bad, it won’t take very long for you to notice something is not right with your vehicle. With most vehicles, you’ll start to notice such things as your engine misfiring, a loss of power when you are trying to accelerate, fuel vapors coming from the vehicle, or dark smoke coming out of your exhaust pipe. 

Though it’s not dangerous to drive your car if it has a bad catalytic converter, this doesn’t mean you should ignore the problem for a long period of time. 

For example, if you notice dark smoke coming from your exhaust pipe, this means your catalytic converter is in worse shape than you realized and should be looked at as soon as possible by a mechanic.

If only a small part of your car’s catalytic converter is plugged, this will only have a minimal impact on your vehicle’s performance. 

However, if the entire catalytic converter is plugged, your vehicle likely won’t run at all. When this happens, it probably means the converter is completely fused, meaning it will need to be replaced as soon as possible for you to get back on the road.

On some vehicles, the catalytic converter will eventually burn completely through, which will also necessitate an immediate replacement. 

When your car has this problem, it often stems from your car’s engine burning too much oil, which means you now have another problem that needs to be corrected. 

Can a Bad Catalytic Converter Ruin Your Engine?

While it’s not dangerous to drive your vehicle when it has a bad catalytic converter, we recommend you don’t let this problem fester indefinitely. If you do, there is an outside chance you could eventually ruin your car’s engine.

Generally, catalytic converters are made to last at least 10 years on vehicles, and in many cases will last much longer. But as you drive your vehicle, the catalytic converter may get clogged or contaminated from dirt and other debris, resulting in it overheating. 

When this combines with an engine that is burning too much oil, this is what leads to the converter burning through and requiring immediate replacement.

When your vehicle’s catalytic converter is actually physically damaged, which can occur from overheating or from debris that may strike it while you are driving, this can lead to your engine getting more and more sluggish, with the end result being a complete engine shutdown. 

Though the sluggishness of your engine will alert you to a problem, you likely won’t know an engine shutdown is ready to happen until it actually does, meaning it could happen anywhere at any time. 

In the case of a catalytic converter that is plugged, you may find that you start your engine, only to have it quit shortly afterwards. If you have this happening over and over, you should get your converter checked by a mechanic. Though it may not necessarily ruin your engine, it won’t do it any good over the course of time.

Can You Drive Your Car if the Catalytic Converter is Missing?

If there is one thing you should remember about catalytic converters, it is that all vehicles are for the most part able to function and be driven in a normal manner when a catalytic converter is missing.

Having said that, we by no means recommend you doing so as a long-term option. As you may or may not know, removing a catalytic converter is very common, especially on vehicles where a driver wants to boost their engine’s horsepower. 

As we mentioned earlier, states have strict emissions standards for motor vehicles, meaning your catalytic converter is needed to keep your car’s exhaust system in check. 

If you choose to remove it and are pulled over by police, you will be ticketed and hit with a fine that could be as much as $250. 

If you think cops won’t notice vehicles that are missing a catalytic converter, you are wrong. Unfortunately, vehicles without a converter become very obvious when on the road.

The most obvious sign of a vehicle with a missing catalytic converter is very loud noises, especially when it is being started or when it is being accelerated. In fact, your vehicle will sound as if it is roaring. 

Also, your vehicle will experience acceleration that is very uneven and jarring, which will also make your vehicle very noticeable to everyone around you, including cops.

Why are Catalytic Converters Stolen from Cars?

If you are like many people, you probably wonder why thieves are so eager to steal catalytic converters from vehicles. After all, since it’s part of the exhaust system, on the surface it seems to be no more valuable that your muffler or exhaust pipe.

However, that’s not the case, and thieves know it. Though much of your catalytic converter is composed of ceramic material, it also contains a number of metals that are considered to be precious metals, such as rhodium, palladium, and even platinum. 

When thieves steal catalytic converters, they are doing so for these precious metals.

Once a converter is stolen, thieves then sell the metal as scrap, where they can make a substantial amount of money.

If you don’t know much about your vehicle’s exhaust system, you may be surprised to learn that it is very easy for thieves to remove a catalytic converter from a vehicle. 

In fact, experienced thieves can do so in only a few minutes. To do so, they simply saw the converter out of the exhaust system. In doing so, your car is then left with damage that will cost thousands of dollars to repair.

How Much Does it Cost to Replace a Catalytic Converter?

When you need to get a catalytic converter replaced on your vehicle, either due to theft or normal problems that developed, we hate to inform you that the job won’t come cheap. 

In fact, a catalytic converter replacement is often one of the costliest repair jobs on most vehicles.

Though the job itself won’t be too hard for an experienced mechanic to perform, the total cost for the job is usually at least $1,000, and for many vehicles will easily exceed $2,000. 

Most of the cost associated with the replacement will be attributed to the catalytic converter itself, which may cost as much as $2,200 brand-new. Easy to install, labor costs for the job are almost always very low. 

Since this repair job can be expensive, you may need to think about whether it’s worth it for your vehicle. If your car is older, has very high mileage, or has experienced other mechanical problems, you may be better off to buy another vehicle. 

If you are experiencing problems with your catalytic converter, remember that you can drive your vehicle for quite some time without much to worry about. However, don’t put the problem on the back burner any longer than necessary. 

From making it harder on your engine to getting fined by police, solving the problem sooner rather than later is a smart decision.

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Zach Reed

Hi, I'm the founder of! Having owned a wide variety of vehicles in my life, I was astounded at how hard it can be to find answers to common automotive questions. Rather than sit idly, I decided to create this website to help others!