You may have started to notice a strange smell coming the exhaust of your car, or maybe you have unexpectedly started to see a significant drop in your fuel economy.
Whatever the situation may be, you’re wondering if the reason for the smell and drop in fuel economy is due to the catalytic converter, while you count and recount the pennies in your piggy bank!
Unfortunately, if your car requires replacement of the catalytic converter, it could be a very dear exercise.
What Is A Catalytic Converter?
A catalytic converter (commonly called a cat converter or just a cat) is an emissions control device that is found in the exhaust of most vehicles.
Internal combustion engines create many harmful toxic gases through their operation and design that are bad for our environment and our health.
Catalytic converters work to convert harmful gases and pollutants into less harmful gases that eventually exit your tailpipe.
From the outside they look similar to exhaust mufflers, but inside they are very different.
The inside of a catalytic converter is a honeycomb of various materials: platinum, palladium, rhodium, and these materials reduce the toxicity of the exhaust gas it comes into contact with.
How do catalytic converters work?
So now we know that catalytic converters change harmful exhaust gas into less harmful gas, but how does that happen? What kind of magic happens inside these little devices?
Catalytic converters are very simple devices, there are no moving parts, and no fancy computer technology involved.
The inside of a catalytic converter contains a ceramic honeycomb component, that is layered with (a mix of platinum, palladium, and rhodium) catalyst particles.
When the vehicle is moving, exhaust gases travel through catalytic converter and three harmful compounds (hydrocarbons, nitrogen oxides, carbon monoxide) are heated and react with the catalyst and change to far less harmful emissions.
Why Exhaust Gasses Are Bad For Your Health?
Before 1975, catalytic converters were not common place equipment. Unfortunately, a lot of the vehicles manufactured during this time, were big muscle cars with huge engines that destroyed our environment and took down our breathing air quality to levels that most humans have only heard about.
There are three major harmful compounds that are in exhaust gas that catalytic converters are designed to eliminate:
- Hydrocarbons – found in unburned gas
- Nitrogen oxides – Which are formed when the heat of the engine forces nitrogen into the air which combine with oxygen
- Carbon monoxide – The byproduct of burning gas
So why are all of these harmful?
Carbon monoxide is poisonous to everyone who breathes air, I mean, that’s basically all animals, including humans.
If that isn’t bad enough to just notice, hydrocarbons and nitrogen oxides produce it’s own smog (which is why big cities like Los Angeles have horrible air quality), nitrogen oxides are even a producer of acid rain!
So clearly we do not want any of these gases in our air, add to that the amount of vehicles on the road today emitting bs gases. catalytic converters are incredibly important!
What Happens To The Harmful Gases?
By now your probably saying, but wait, where does it go? there are still gasses coming out my tailpipe.
Yup, and though these gases are still not great for our earth, they are far far less harmful – through the conversion process of a catalytic converter, and it’s up to 90% of a vehicle’s tailpipe pollutants are removed.
The carbon monoxide gases react with the catalyst particles and change into carbon dioxide, which we, and all animals exhale, and trees can use.
Hydrocarbons breakdown and change into carbon dioxide and water, and nitrogen oxides are torn asunder in the cat converted and changed back into nitrogen and oxygen particles before entering the atmosphere. Win, win, win!
Where Is My Catalytic Converter?
The catalytic converter is located under your car within the exhaust system. Usually found in the middle of the exhaust, it is located in between the exhaust manifold and the muffler.
It is usually, but not always, welded into the exhaust pipe from the factory while many replacement catalytic converters are clamped.
Some cars might even have two catalytic converters as is the case in dual exhaust systems because there is one catalytic converter for the exhaust pipes.
Some newer, higher end cars have at least two catalytic converters in a line in order to further reduce exhaust emissions.
How Do I Know If Something Is Wrong With My Catalytic Converter?
There are some signs that can tell you if your catalytic converter has failed. Here are some tells to look for:
#1. Your Car Failed Its Emissions Test.
In many states in the USA emission testing is a regular requirement for vehicle owners to follow. If your catalytic converter is faulty or not working not going to work very well, your car will likely be producing more exhaust fumes that expected.
#2. Engine Check Light Is On.
An engine check light can be a number of things, and due to the complexity of most cars today, it would be impractical for a dash light to indicate everything that could go wrong!
If your catalytic converter is failing, there is a chance that you o2 sensor in the exhaust could be sending a signal to the ECU telling the car engine nothing is right.
When this happens it causes you engine check light to come on, which means you should head directly to your local garage for a checkup.
The only way to really know if the engine check light is caused from poor cat fix performance is to take it to a garage who will do a diagnostics test.
The mechanic will connect their diagnostics tool to your vehicle and it will scan the ECU for error codes telling the mechanic exactly what is wrong.
If you’re engine check light is on it’s not necessarily an indicator you have a bad cat, but if you’re experiencing any of the following symptoms its probably a good indication.
#3. Your Exhaust is Producing a Rotten Egg Smell.
There is a small level of sulfur in the fuel you vehicle runs on. The rotten egg smell is caused by a compound called hydrogen sulfide.
Typically, hydrogen sulfide would be converted into an odorless sulfur dioxide, but if your catalytic converter is not working due to improper exhaust temperatures, the hydrogen sulfide will exit the exhaust pipe and create a horrible rotten egg smell.
#4. Your Vehicle is Not Accelerating Like It Used.
One of the major issues with a catalytic converter failure is it can build up excess carbon in the honeycomb design. This build up and cause a partial block of the catalytic converter, which causes a relationship experience when driving.
Internal combustion engines run on air (as well as fuel and ignition), wherever there is a block in a catalytic converter it can help create an improper amount exhaust backpressure which in turn compromises air flow in the vehicles exhaust system.
Less air flow means less power means poor acceleration.
So, next time you notice your car feels a little underpowered while trying to get and overtake someone, the cause may be due to a catalytic converter issue.
#5. You’re Noticing Fuel Economy Problems.
Considering gas is so expensive, even the smallest change in your vehicles fuel economy can cause a world of difference at the pumps and in your wallet.
If you are driving with a blocked catalytic converter, the ECU will not be receiving the correct levels of air flow for the engine to perform efficiently, and as a result the engine will likely be working harder to produce the same power, which means pumping in more fuel.
To put it into perspective, say you suddenly have to run up a hill, index the increase in effort you need to do just to continue at the same speed and distance.
What Are The Reasons That Catalytic Converters Fail?
Catalytic converters do not have moving parts so you’d think they would last forever right? Well the good news is they can, and typically are meant to last the 10-15 year lifespan of a car!
But this only holds true if everything else in the vehicle is functioning perfectly, which it usually isn’t. All the parts in your vehicle work together, if one fails to operate properly it can hurt the other parts.
Secondly, it assumes you won’t be using the car after 15 years! in 2019 the average age of a car in the US was almost 12 years, meaning a massive number of cars are right around that 15 years threshold.
In addition to normal aging there are a few other causes of catalytic converter’s failure:
- Oxygen sensor not functioning properly
- Bad spark plugs or wires
- Unburnt fuel entering the exhaust
- Oil entering the exhaust
- Antifreeze entering the exhaust
How Much Does It Cost To Replace A Catalytic Converter?
The replacement costs of catalytic converters, like most vehicle repairs, can vary dramatically.
Your Car Make/Model
If you own a ‘93 Toyota Corolla, your catalytic converters replacement cost is going to be a lot different than an ‘05 Jaguar XK8. Depending on the model you own, the catalytic converters itself could be a few hundred bucks, or it could be a couple thousand.
Replacement Quality
Not all catalytic converters are created equal. You can get a universal fit catalytic converter for under $100, all the way up to a purpose-built catalytic converters for your model at upwards of $1000.
Not only will you see price differences in the monetary cost of a replacement catalytic converters, but there can be a dramatic difference in the internal design of a catalytic converters.
One of the main factors that keeps them expensive are the precious metals (palladium, platinum) used in the catalytic process, which might explain why catalytic converters are such a popular target for thieves.
Less expensive replacement c catalytic converters will typically have a much lower ratio for these precious metals than their more expensive counterparts, which means they are less efficient and subject to failing quicker.
More expensive units will often have much higher catalyst densities, up to 6x more than cheaper options.
Labor
Average shop labor rates are typically $70-$130 an hour, with a more budget-friendly garage allowing for potentially less expensive repairs.
It is also important to consider how lengthy the work is required to replace the cat.
The work to replace the catalytic converters specifically will be different for every car, and depends highly on the placement of the cat, the level of accessibility to replace the unit, and what the mechanic has to do to complete the replacement (They might need to cut out the old welded catalytic converters and clamp in the new one), amongst other considerations.
With dual exhaust, one could expect you might pay additional in replacement parts and double for labor.
Diagnosis & Repair of Additional Issues
Do not forget to also consider that there may be something else wrong with the vehicle that has caused the catalytic converters to fail. For example, a fouled spark plug or a faulty oxygen sensor could also mean you have to pay for these repairs as well.
Typical Cost of a catalytic converters Replacement
Even though the cost of replacement can widely vary depending on your choice of catalytic converters quality, and of course, the type of vehicle you have, catalytic converters are typically priced in the range of $1000-2500.
If you have a rare or specialty vehicle, you could expect much higher costs again.