Catalytic Converters and the Important Role They Play

Internal combustion engine (ICE) cars produce carbon monoxide, nitrogen oxides, and hydrocarbons that harm people and environment. Although there have been great strides in making ICEs as efficient as possible, these hazards remain present in the exhaust. With environmental regulations getting stricter each year, automakers looked to find a way to reduce the amount of pollutants expelled by their cars even further. And this is when the usefulness of the catalytic converter comes into the picture.

What is a catalytic converter?

Regardless of how harmful engine byproducts can be, all they are really, is just a clump of atoms. Catalytic converters are placed in a car's exhaust system with the purpose of reducing nitrogen oxides, carbon monoxide, and hydrocarbons by breaking down as much of the toxic elements as possible before the exhaust pipes release them into the air.

There's not much going with the catalytic converter in terms of appearance. It's simply a metal tube with an input and output pipe, with one end attached to the engine and the other to the exhaust tail. But inside is where the magic happens.

How a catalytic converter works

There are two main stages to how a catalytic converter works. The first is the reduction catalyst, and the second is the oxidation catalyst. The reduction catalyst is in charge of removing the nitrogen oxides, and it does this by breaking down the nitrogen atoms from the compound, thus producing harmless nitrogen and oxygen gases. The oxidation catalyst, on the other hand, oxidizes carbon monoxide, and transforms it into carbon dioxide.

Modern catalytic converters come with an added oxygen sensor that detects the amount of oxygen present in the exhaust gases. The sensor then adjusts the engine's air intake to keep the fuel-to-oxygen optimal while ensuring there's enough oxygen for the catalytic converter to run properly.

Aside from reducing harmful emissions, catalytic converters also serve muffling functions, helping the engine run quieter.

The downside to catalytic converter is that they only work at high temperatures, and it takes them 10 to 15 minutes to warm up properly. This means your car is essentially expending harmful gases into the air during the first few minutes of starting your engine. A good tip to know when you have an old car that needs to undergo emissions testing.

Why are they so expensive?

For a vehicle component that looks like an ordinary exhaust pipe, catalytic converters are quite pricey. In fact, they can cost as much as a perfectly good second-hand car. This is because in order for the converter to do its job, it must use precious metals such as palladium, rhodium and/or platinum. These metals are hard to come by, and they drive the price of the catalytic converter up.

Fortunately, catalytic converters are often solidly built, and save for a major road accident that damages the assembly, you won't need to replace yours over the life of your car.

Catalytic converter maintenance

Catalytic converters are maintenance-free, but they do have a lifespan. Experts say it's between 150,000 to 160,000 kilometers. When your odometer reaches these numbers, it's time to have your converter cleaned or replaced.