How To Tell If Catalytic Converter Is Bad (5 Key Signs)

What Can Damage A Catalytic Converter

Apparently, when a component in your engine or the drive-train starts failing, you’d definitely know!

Yes, you’d know because your car would start showing up different symptoms and signs of failure, which mostly includes loss of traction or engine power. But do you know how to tell if catalytic converter is bad?

A bad catalytic converter would cause the check engine light to illuminate, and you may start hearing annoying noise from your engine as you drive. There are pretty other signs a failing catalytic converter may show up, and they are explained in this article.

However, to better understand this article, let’s go through the functions of a catalytic converter, and what could make it go bad!

What Does The Catalytic Converter Do?

The catalytic converter is an important part of a vehicle’s emissions system. Its main function is to convert harmful emissions – that are coming from the engine – into steam-like gases and pass them through the exhaust pipe.

It is called the “Catalytic Converter” because it traps the harmful emissions from your engine in a “catalyst” chamber, where the emissions are converted into safe gases. Also, the catalytic converter splits unsafe molecules, turns them into gases released into the air.

Basically, catalyst converters are built to be very strong and last through the lifespan of the vehicle they are attached to. But, several factors can cause the converter to fail, or get physically damaged.

Once the converter the bad, most apparently, you’d notice a drop in the performance of your car, and the gases coming out from your exhaust pipe would be very dirty and harmful.

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What Can Damage A Catalytic Converter?

The catalytic converter may go bad when you drive in extreme conditions. Also, if there’s a leak in your car’s exhaust system, it can cause oil to drop on the body of the converter, and over time, that could cause corrosion.

Apparently, when the converter corrodes, it’d become weak and won’t be able to do its job as expected. Also, coolant leaks can block the catalyst converter surface, causing it not to function as supposed.

But well, if you can detect the signs of a failing catalytic converter and get it fixed, you’d be on the safe side. In contrast, if a bad catalytic converter is not fixed, it can, over time, ruin an engine, resulting in costlier repairs.

How To Tell If Catalytic Converter Is Bad

How To Tell If Catalytic Converter Is Bad

When you start noticing any of the signs explained before, it is a call to check your vehicle’s catalyst converter.

1. Engine Misfiring

If you just had an oil change, and your gas tank is full to the marked level, yet your engine seems to be misfiring, that’s a call to check your catalyst converter.

A bad cat system can directly affect the engine of modern vehicles because, in newer cars, everything is connected to a central computer.

Thus, if one of the car components starts failing, the central computer would get the signal and display the respective warning icon for that issue on your car dashboard. If the issue persists, that’s when your engine starts getting affected.

2. Check Engine Light Is On

Actually, there are quite many actions that can cause the check engine light to come on. Basically, when a component connected to your car’s engine starts failing, the check engine light would illuminate.

So, if you’ve ruled out other possible triggers that could activate the check engine light, next is to have your cat converter checked by a mechanic.

Yes, unless you’re experienced, a regular car owner may not be able to detect a bad catalyst converter – however, unless the converter is physically damaged.

3. Decrease In Fuel Efficiency/Economy

A failing catalyst converter won’t be able to process the harmful emissions coming from your engine; thus, those harmful molecules may fall back into the engine or escape from other possible spaces.

When your engine is filled with harmful molecules – that should have been released into the air through the exhaust system – the engine would tend to use more fuel to keep running at its possible best.

Again, it is important to note that there are other scenarios that can cause a decrease in fuel efficiency or economy. However, this is to notify you that a bad catalyst converter is also one of the possible causes of the decrease in your car’s fuel efficiency rate.

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4. Very Dirty Gases Coming Out From Your Car’s Exhaust Pipe

Yes, the exhaust system is meant to remove the engine emissions into the air as gases. However, if your car’s catalytic converter is in good shape and functional, the gases won’t come out dirty (very dark); they’d rather be released through the tailpipe as “steams.”

The dirtiness is a result of the carbon buildup inside the exhaust system due to a bad cat converter.

5. Rattling Noise

Another thing your may notice when your cat converter is no longer in good shape is “rattling noise.” You’d start hearing loud rattling noise, which you may not particularly point out where it’s coming from.

The catalytic converter comprises smaller components; so, when the converter is bad, those components may start dancing around inside the chamber, and that could be the cause of the noise.

What Happens When The Catalytic Converter Goes Bad?

When you’ve got a bad or failing catalytic converter, you’d start experiencing any (or all) of the signs mentioned above.

Notwithstanding, your car would still drive normally, but if you get caught up in a situation where your car needs to pass through a vehicle test, apparently, you’d be paying a fine because your car won’t pass the test – specifically, the emissions test.

Conclusion

When the gas coming out of your car exhaust pipe is very dark and dirty, or your engine is misfiring too often, those are signs for you to check the cat converter.

Well, to replace a bad catalytic converter would cost you a substantial sum, but not as expensive as replacing a wrecked engine.

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