Symptoms of a Bad Catalytic Converter | Autance

It is not unusual to have catalytic converter problems. This is despite the fact that vehicle manufacturers design these devices…

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Symptoms of a Bad Catalytic Converter | Autance © Symptoms of a Bad Catalytic Converter | Autance

It is not unusual to have catalytic converter problems. This is despite the fact that vehicle manufacturers design these devices to last the lifetime of the car. A mechanic can help you identify the problem; however, you can also zero in on the issue if you are familiar with the signs of a bad catalytic converter.

Engine Misfires

What is a catalytic converter? This is an important device that converts harmful gases into less harmful compounds. These harmful gases are the byproducts of combustion in the engine. They can include hydrocarbons, nitrogen oxides, and carbon monoxide. The catalytic converter produces carbon dioxide, water, oxygen, and nitrogen from the harmful gases. As such, any problem with the catalytic converter can produce unwanted effects in the engine. One of them is misfires.

Can a clogged catalytic converter cause a misfire? Yes, it can. A clogged catalytic converter prevents the more efficient flow of exhaust gases from the engine. This disruption can heat the gases in the engine. They ignite, independent of the normal combustion process. This leads to engine misfires.

If you notice engine misfires, it is best to have a mechanic check it at once. Such a problem can damage the different components of the engine.

Reduced Engine Performance

What happens when a catalytic converter goes bad? Aside from engine misfire, you will also notice a reduction in engine performance. Clogged catalytic devices prevent gases from escaping through the exhaust tailpipe. This creates back pressure.

The increased pressure between the catalytic converter and the engine can affect the working performance of the engine. When running, the engine continues to produce gases from the combustion process. Unfortunately, these gases get trapped in the engine because of the clogged catalytic converter.

The engine is unable to “breathe”, like it is choking. You can feel the vehicle jerk. You may also notice your car as if it is not getting enough fuel whenever you step on the gas pedal. You can also have engine stall if there is a sudden burst of the back pressure.

Related Post: Best Catalytic Converter Cleaners

Loss of Power with Load

One of the most telling bad catalytic converter symptoms is loss of power during acceleration or under load. You may notice your vehicle having a difficult time going up a hill. Unfortunately, some mechanics can misdiagnose this.

There is a very simple test that will help you determine if the poor acceleration is due to catalytic converter problems or not. Ask someone to depress the gas pedal so that the engine will run between 1800 and 2000 RPM. Feel the exhaust pressure coming out of the tailpipe. If it is hot, then you know that you have a clogged converter.

Before you think about replacing it, you might want to use one of the best catalytic converter cleaners first. These products help break down carbon buildup in the exhaust system as well as the engine.

Reduced Performance of the Exhaust System

A failing catalytic converter can also reduce the ability of the exhaust system to remove toxic gases from the car. As gases get trapped in the front section of the clogged device, it becomes more difficult for gases to get out through the tailpipe.

The trapped gases also tend to accumulate deposits. This can further aggravate the blockage that is already present in the system. And if ever these carbon deposits get dislodged, you can expect a thick and dark smoke coming out of your tailpipe.

Increased Emissions

We know that the main job of a catalytic converter is to turn the harmful gases into less harmful ones. If there is a problem with the device, then it would be impossible to produce harmless gases. What you will get is an exhaust that is rich in carbon monoxide, nitrous oxide, and hydrocarbons. In effect, you may not be able to pass your vehicle emissions test.

This is bad for the environment. It can further increase carbon emissions and contribute to global warming. People who inhale these gases are also at risk of developing serious respiratory illnesses.

Smell of Rotten Eggs

One of the signs of a bad catalytic converter is the noticeable smell of rotten eggs. There are some types of gasoline that contain sulfur. When this type of fuel goes to the engine during the combustion process, a chemical reaction takes place. The sulfur-containing fuel turns into hydrogen sulfide.

If your catalytic converter is working in a normal manner, it will turn the hydrogen sulfide molecules into sulfur dioxide. This is an odorless compound that goes out through the exhaust together with the other gases.

A failing catalytic converter cannot produce sulfur dioxide from hydrogen sulfide. As such, you may notice the characteristic smell of rotten eggs.

“Check Engine” Warning

There are many reasons why you may get a “Check Engine” warning. One of them is a problem in the catalytic converter. Modern cars come with a number of sensors that are able to monitor the working performance of the catalytic converter. These include the air fuel ratio sensor and the oxygen sensor. They keep track of the levels of exhaust gas in the exhaust system.

If the car’s computer detects an abnormality in the performance of the catalytic converter, it triggers the Check Engine warning light. This helps to notify or alert the driver of a potential problem. You can never identify the actual problem right away. That is why it is best to have your car scanned for diagnostic trouble codes.

Poor Fuel Economy

A failing catalytic converter can put strain on the engine. It will not be working as efficiently as it should. It will have to work harder to push the gases through the clogged exhaust system. This will make the engine consume more fuel than necessary.

Overheating can also reduce the performance of the engine. It can damage critical engine components that can also have an effect on fuel economy. Over time, you may face the prospect of an expensive engine rebuild if you do not work on the problem at once.

Problems in catalytic converters can produce a number of symptoms. Some of these are easy to diagnose, while others may require a mechanic for proper identification.


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