Can You Drive With A Bad Catalytic Converter [And For How Long]?

Do you have a vehicle with a bad catalytic converter, and you’re wondering how long you’ll be able to drive it? You’ve come to the right place, for we have researched this question, and we have the answer for you.

A bad catalytic converter increases your car’s emissions, but it doesn’t prevent your car from running. A clogged catalytic converter can affect the performance of your car because exhaust gases cannot easily exit. Your car’s engine will suffer from an increase in exhaust gas pressure.

Keep in mind that reducing car emissions through a catalytic converter is mandated by law. Learn more about this in the succeeding sections, including whether or not you could get in trouble for driving a car with a bad catalytic converter. Read on!

Catalytic converter installed in a modern car, Can You Drive With A Bad Catalytic Converter And For How Long?

What is a catalytic converter?

Let’s talk about the catalytic converter—what it is and what it does—before we proceed.

A catalytic converter is part of the emission control of your car. It uses high temperatures inside its chamber to convert toxic exhaust gases into less toxic forms.

Catalytic converters need to warm up, and they produce the largest amount of toxic exhaust during the first five minutes as they get to their ideal temperature. This is why some car models have installed a pre-cat to mitigate the delay that the main catalytic converter needs as it warms up.

Exhaust system of a modern car

What is a pre-cat?

A pre-cat is a small catalytic converter between the engine and the main catalytic converter. It heats up faster and can handle the toxic exhaust gases from the engine while the main catalytic converter warms up.

The pre-cat effectively reduces toxic emissions coming from a cold start.

Automobile manufacturers like Toyota install a pre-cat on vehicle models that they want to get a ULEV (Ultra Low Emissions Vehicle) rating.

What is an electrically heated catalytic converter

Some automobile manufacturers developed a catalytic converter that can achieve operating temperatures through an electronic heater. This version has heating coils inside the chamber that starts to heat the catalytic converter as soon as the engine starts up. This brings the catalytic converter to minimum operating temperatures faster.

Vehicles equipped with this type of catalytic converter can also qualify for a ULEV rating even without a pre-cat.

What happens when you drive with a faulty catalytic converter?

Used catalytic converter of a car exhaust system

As we mentioned earlier, you can still drive your car even with a bad catalytic converter.

However, your catalytic converter can become clogged if you continue to drive your car. A completely clogged catalytic converter can prevent your engine from even starting.

Engine overheating

Inside a catalytic converter are layers of honeycomb mesh that can quickly become clogged if the catalytic converter is faulty.

Part of the function of the exhaust system is to push hot exhaust gases out of the engine. These hot gases will eventually get to the catalytic converter, where they will convert the toxic emissions.

The heat flowing out of the engine will not be able to easily exit through a clogged catalytic converter. This creates a backflow of pressure where the engine tries to push out more hot exhaust gases than the exhaust system can let out of the car.

A clogged catalytic converter leads to a loss of power and ultimately overheating of the engine.

Failing emissions test

A bad catalytic converter can cause you to fail your Vehicle Emissions Inspection Test.

Vehicles owners need to bring their vehicles for an emissions test at a specified date. If your vehicle fails the emissions test because of a bad catalytic converter, you get another 30 days to fix the catalytic converter and resubmit your car for a free retest.

Missing the appointed date for the emissions test by more than 30 days will subject the owner to a $20 late fee.

Your vehicle will get a denial of registration if your vehicle fails the emissions test or does not go through the emissions testing. You will not be able to renew your registration until you comply and pass the emissions test.

Thus, putting off replacing the catalytic converter can lead to a registration denial, and you will no longer be able to drive your car legally.

Driving a car without emissions requirements

It is an infraction to drive a car that has not complied with emissions requirements. Police officers can access the DMV database and check a car’s registration to find out if a vehicle is noncompliant.

The first citation for operating a vehicle that has not passed an emissions test can result in a fine. You will get a fine each time your vehicle is stopped and found non-compliant. Keep in mind that each fine is higher than the last.

Each time you drive a car that did not pass the emissions test and get stopped is a separate violation. Thus, it is possible to get multiple infraction citations before you get the registration denial.

As we’ve mentioned at the start of this article, you can still drive your car even with a faulty catalytic converter. However, keep in mind that multiple citations can become expensive fast, and it can ultimately become more expensive than replacing your catalytic converter.

This EPA-compliant catalytic converter is available on Amazon. Check it out through this link.

Why Are Catalytic Converters Getting Stolen?

Catalytic Converter in Exhaust System

Your catalytic converter contains precious metals like platinum, rhodium, and palladium to effectively convert the toxic exhaust gases from your engine. Thieves steal catalytic converters and sell the precious metals inside.

Platinum costs up to $1,000 per ounce, and palladium can easily exceed $2,000 per ounce.

The NICB (National Insurance Crime Bureau) reports that there were 3,389 reported cases of a stolen catalytic converter in 2019. This number jumped to 14,433 reported cases in 2020.

The value of palladium increased because of the war between Russia and Ukraine, leading to more catalytic converter thefts.

How can you prevent catalytic converter theft?

Although catalytic converter theft is on the rise, there are many things that you can do to prevent your catalytic converter from getting stolen.

Install a vibration-sensitive car alarm

Newer car models have security systems that are sensitive to vibrations.

Thieves need to saw off the tubes that connect your catalytic converter to the rest of your exhaust system. The vibration from sawing can trigger your car alarm, and it will go off.

Even older cars can install a car security system that is sensitive to vibrations coming from the car.

Install a protective device

The rise in catalytic converter thefts created a market for protective devices that will make it difficult to rob your catalytic converter. Companies now manufacture and sell protective devices that you can install under your car to protect you from theft.

Pipe shielding

Catalytic converter of a modern car

The simplest protection available is shielding that is installed on the pipes that lead to your catalytic converter. The shielding makes the exhaust pipes thicker, and thicker pipes mean that it will take the thief longer to get your catalytic converter.

Although this will only delay the thief, this slight delay could be all it takes to get alerted to the theft.

Steel Cable

Another simple and cheap way to protect your catalytic converter is to weld steel cables onto it and to the frame of your car.

Catalytic converter thieves will likely have with them a saw to saw off your catalytic converter, but the probability is low that they also have bolt cutters with them to cut through a thick steel cable.

Steel shields or steel cages

Companies are selling steel shields or cages that cover the catalytic converter. These cages or shields are riveted to the steel frame of your car. A thief will have to cut through the shielding or cage before he can get to your catalytic converter.

The shield or cage can discourage a potential thief once he realizes that getting your catalytic converter will take a long time.

The Cat Security catalytic converter protection shield (fits Toyota Prius 04-09) is available on Amazon. Check it out through this link.

Mind where you park

Picking a safe area for parking your car

One of the best protections against car theft is parking in the right places. Park your car inside your garage all the time whenever you are at home.

Here are some tips on where to park if you’re traveling and parking inside your garage is not an option:

Pick brightly lit areas

Parking under streetlights or in brightly lit areas can discourage thieves. Thieves prefer working under cover of darkness. Bright lights can easily expose what they are doing and lead people to investigate.

Highly populated locations

Park your car in highly populated locations to discourage thieves. Thieves will avoid stealing your catalytic converter if your car is parked in a location where there are many witnesses.

Security camera

Park your car in areas where there are security cameras in the vicinity.

Security cameras can capture theft on video. Thieves are normally aware of the presence of security cameras in the vicinity. They will avoid targets in areas with security cameras that can capture their crime on video.


Catalytic converter installed in a modern car

Although you can still drive your car despite the bad catalytic converter, it is not a good idea to do so. Consider the potential damage to your engine plus the failure to pass the emissions test. Both situations should be enough to motivate you to have your catalytic converter fixed ASAP.

If you enjoyed reading this article, you might find the articles below equally enjoyable to read:

Does A Catalytic Converter Reduce Power Or Affect Mileage?

Clogged Catalytic Converter – How To Tell And What To Do?

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