How Do You Know If Your Car's Catalytic Converter Is Faulty?

How Do You Know If Your Car's Catalytic Converter Is Faulty?

15 July 2022
 Categories: Automotive, Blog


If you drive a modern car, it is probably fitted with a catalytic converter mandated by authorities to help keep pollution levels in check. This component is fitted within the exhaust system and has an effect on engine performance if it starts to go wrong. If you suspect issues, what should you be looking for?

How the Converter Works

Catalytic converters trap carbon monoxide and other harmful particles. Inside the outer casing, you'll find a honeycomb of narrow passageways treated with a catalyst. As the exhaust gases are forced through these passageways, a chemical reaction will take place and this serves to filter out the worst pollutants.

When Things Go Wrong

The component is designed to work perfectly when the engine mixture is correct, and if you are experiencing problems upstream, the "cat" can also be affected. For example, if the fuel mixture is too rich, this can lead to an excessive amount of carbon deposit and potential blockage. Sometimes, fuel injectors will malfunction and allow too much fuel to get into the combustion chamber. This may find its way out through the exhaust and get trapped within the catalytic converter, damaging the substrate and also blocking those narrow passageways.

Check the Engine

One of the first signs of a problem may simply be that ubiquitous "check engine" light. You will then need to plug the diagnostic tool into the receptor to receive a failure code, telling you if the converter is to blame.

Bad Performance

Alternatively, you may notice poor performance as the converter becomes increasingly clogged. As the exhaust gas cannot get through, it will back up towards the engine manifold instead. When the valves open to expel more fumes, this will cause additional pressure within the combustion chamber, markedly reducing performance.

Poor Consumption Figures

At the same time, you will certainly spend more at the pump. The engine ECU will try to compensate for poor performance by injecting more fuel into the system, and your economy figures will tank instead.

Audible Evidence

If you can hear some strange rattling noises coming from underneath the rear of your car, the internal components of the converter could be broken. This noise will be particularly noticeable during acceleration or when you start the vehicle and will only worsen until you take action.

Acting Quickly

You will need to act quickly to repair your catalytic converter, as you may otherwise struggle to start the vehicle. So, take the vehicle to an auto repair technician at the first signs of a problem.

About Me
Arthur's Top Auto Blog

Hello! My name is Arthur and this is my auto blog. I would like to welcome you to my new website and to tell you a little bit about myself. I have always been fascinated by automobiles. My dad used to run an auto repair shop and I spent many happy summers helping out around the place. I didn't follow my dad into the auto business. Instead I trained to become a lawyer. Despite this fact, I have still retained my passion for cars and I still have the knowledge passed onto me by my dad. I hope you enjoy my blog.

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