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-con? How long can you drive before you have to replace it? What if your catalytic converter is stolen?
Let’s answer some of these questions.
What Is a Catalytic Converter?
As mentioned above, a catalytic converter is an essential part of a vehicle’s exhaust system. It helps lower the number of toxic pollutants emitted into the air by converting hazardous combustion gases into less harmful substances, like water vapor and carbon dioxide.
This is done by exposing these fumes to chemicals and metals inside the converter to prompt chemical reactions that transform otherwise toxic pollutants into relatively harmless ones. Let’s break down how a catalytic converter functions a bit further.
What Does the Catalytic Converter Do?
A purpose of a catalytic converter is to use a chamber called a catalyst to change the harmful compounds from an engine’s emissions into safe gases, like steam. It works to split up the unsafe molecules in the gases that a car produces before they get released into the air.
The catalytic converter is located on the underside of a vehicle and looks like a large metal box. Two pipes are coming out of it. The converter utilizes these two pipes and the catalyst during the process of making the gases safe to be expelled.
Gases are brought in from the “input” pipe connected to the engine of a vehicle. These are blown over the catalyst, which causes a chemical reaction that breaks apart the pollutants. The less-harmful gases now travel through the second pipe, or the “output,” that is connected to a car’s tailpipe.
Core purpose of catalytic converters
The core purpose of catalytic converters in automotive systems is to reduce the emission of harmful pollutants from an engine’s exhaust gases and make them more environmentally friendly.
Their effectiveness and reliability are vital not only for maintaining vehicle performance but also for contributing to efforts to reduce atmospheric pollution.
Can You Drive Without a Catalytic Converter?
The short answer is yes.
Temporarily driving without a catalytic converter won’t damage your car’s engine. However, it may cause some performance issues.
The real question is: Why would you want to drive without one? Driving without a catalytic converter will emit harmful exhaust gas into the atmosphere.
Plus, laws around catalytic converters and emission tests are very strict (for a good reason).
Unfortunately, these laws around the emissions test still apply even if your catalytic converter has been stolen.
Let’s take a closer look at the legal angle.
Is it Illegal to Drive Without a Catalytic Converter?
Yes, it’s illegal to drive without a catalytic converter in most states of the US. However, some exceptions made by the Environmental Protection Agency (EPA) make driving without a CAT legal.
While the law differs from state to state, it’s best to play it safe and ensure your vehicle always has a functioning catalytic converter fitted. The Clean Air Act of 1970 mandates that all vehicles must be fitted with carb compliant catalytic converters from the factory.
What if your vehicle didn’t come with a catalytic converter? We’re glad you asked.
Most cars manufactured before 1970 (when the Clean Air Act was instated) didn’t come with factory-fitted catalytic converters. For this reason, some states (like Georgia) will allow you to pass respective emission checks if your vehicle is older than 25 years.
We’ve established that it’s generally illegal to drive without a CAT.
Now, let’s explore the safety aspect.
Is it Safe to Drive Without a Catalytic Converter?
Yes, you may be physically safe driving without a catalytic converter, but you won’t be legally safe (as mentioned above).
As a critical component of your car’s exhaust system, the catalytic converter reduces air pollution. So, driving with a broken catalytic converter (or no catalytic converter at all) won’t cause a crash.
Still, you’ll want to replace it as soon as you notice you have a stolen or failing catalytic converter!
Here’s why:
Driving without your car’s catalytic converter means you’ll expel very high concentrations of carbon monoxide — an extremely harmful emission. Most deaths caused by carbon monoxide poisoning occur while operating a vehicle inside enclosed spaces.
Plus, if you have a bad catalytic converter (clogged, broken, or faulty catalytic converter), it’ll severely hinder your car’s engine performance.
Let’s look at how driving without a cat converter affects your vehicle.
What Happens If You Remove Or Bypass A Catalytic Converter?
Driving without a catalytic converter can lead to several consequences, both legal and mechanical. Here are some of the potential outcomes:
- Increased emissions – Without a catalytic converter, your vehicle will emit higher levels of harmful pollutants like carbon monoxide, hydrocarbons, and nitrogen oxides, adding to air pollution.
- Legal penalties – In many areas, it’s illegal to operate a vehicle without a catalytic converter or with a deliberately tampered one. You may face fines, penalties, or even have your vehicle impounded if you’re caught driving without it.
- Failed emissions test – Many jurisdictions require emissions testing to ensure that vehicles meet specific air quality standards. Without a catalytic converter, your vehicle will fail these tests, potentially resulting in fines, an inability to renew your registration, or mandatory repairs.
- Poor engine performance – The engine control module in modern vehicles is designed to work with the catalytic converter in place. Removing or bypassing the converter can cause the ECM to receive incorrect data, leading to poor engine performance, reduced fuel efficiency, and potential damage to other components such as oxygen sensors.
- Noise increase – Catalytic converters also act as a partial muffler, reducing exhaust noise. Removing the converter can result in a louder exhaust sound, which may violate local noise regulations.
- Potential damage – Operating a vehicle without a catalytic converter can lead to increased exhaust temperatures, which may cause damage to other components in the exhaust system.
Common reasons for catalytic converter failure
For the most part, catalytic converters are durable parts that can be expected to last for about 10 years or even longer if you take good care of your car or truck.
Over time, they can become clogged or damaged, especially if you’ve put the wrong fuel or low-quality fuel into your vehicle.
Catalytic converter failures typically fall into one of a handful of categories:
- Structural damage (such as corrosion or damage from road debris)
- Overheating
- Clogging
- Contamination from fuel additives or oil
Warning signs of a failing catalytic converter
Catalytic converter issues aren’t always obvious. They can manifest themselves in several ways, including:
- The check engine light comes on.
- Fuel consumption increases for no obvious reason.
- Strange rattles come from the engine.
- Your car experiences sluggish acceleration.
- The engine misfires.
- There’s foul-smelling or darker-than-usual exhaust.
Most newer vehicles have multiple sensors that keep track of the performance of the engine and alert you if your catalytic converter is no longer operating within acceptable parameters.
Even if your car is otherwise running well, don’t ignore a check engine light. Get your catalytic converter inspected. Catching issues early could prevent more costly repairs in the future.
How much does it cost to replace a failed catalytic converter?
You can expect to pay between $1,000 and $3,000 for a replacement catalytic converter, depending on the make and model of your vehicle. Original equipment manufacturer or OEM catalytic converters usually cost more than aftermarket ones but often last longer.
If you’re considering an aftermarket converter, make sure it complies with any relevant emissions requirements in your state.
How to care for a catalytic converter
You can extend the life of your catalytic converter by taking good care of it and practicing sensible driving habits.
- Fix mechanical problems promptly. Small problems can cause more damage than you think, and a misfiring engine could lead to carbon buildup on the honeycomb surface inside the catalytic converter, preventing it from doing its job.
- Drive at a moderate speed when possible. Running at high speeds for a long time can accelerate existing damage to a converter.
- Avoid towing heavy trailers or overloading the vehicle. Both can overwork the engine.
- Use high-quality gasoline brands. Cheaper brands can shorten the life of a catalytic converter dramatically due to impurities in the fuel.
- Follow the manufacturer’s recommended oil-changing schedule, and choose high-quality oils.
Catalytic converters play an important role in protecting the environment and keeping your engine running smoothly. They may cost thousands of dollars to replace, but it’s a worthwhile investment.
If you’re having issues with your vehicle, whether it’s rattling noises or a check engine light, take a trip to a garage as soon as possible for peace of mind.
How Can You Prevent Catalytic Converter Theft?
Thankfully, there are a few preventative measures you can take to deter the theft of your catalytic converter.
Install a Protective Device
Catalytic converter theft has become so prominent that companies have started to sell protective devices. These installations make it impossible for anyone to cut off your catalytic converter.
Unfortunately, high-quality devices and their installation will likely run you a few hundred bucks. However, it could save you thousands of dollars on catalytic converter replacement.
Vibration-Triggered Alarms
Some newer vehicles have a security setting that triggers the alarm when it senses vibrations. The sawing of your catalytic converter will be enough to set off these alarms.
Mindful Parking
When you are at home, you can park in the garage to help avoid catalytic converter theft. What about when you are on the go? When your garage is not an option, here are some parking tips to keep in mind:
- Brightly-lit areas: Parking under street lights or in brightly-lit locations can help deter theft.
- Highly populated locations: If the lot or parking garage you are in is seeing a lot of foot traffic, it will be hard for someone to steal your catalytic converter without being caught.
- Security camera: Keep an eye out for security cameras in your parking area and try to find a spot visible to the cameras.
At best, these practices can deter the theft of your catalytic converter. Otherwise, it may help the authorities catch the individual who stole your vehicle parts.