Catalytic converter produces smoke when it malfunctions. But, what about black smoke?
So, black smoke is coming out of your catalytic converter? And, you are wondering what’s wrong with your engine and if it would lead to serious problems. Perhaps you’re concerned about its potential risks.
No, a bad catalytic converter doesn’t cause black smoke. Overburning of fuel results in black smoke. The proportional mix of oil and fuel ratio can also cause the issue. Furthermore, oil and fuel ratios that are contaminated also contribute to this problem.
That’s just the tip of the iceberg and more to deep dive. So, come along with me as I detail everything.

What Is Black Smoke and Is It Dangerous?
Black smoke is what it is called. When the engine burns too much fuel or there is contamination in the fuel, it causes black smoke. White smoke is usually thinner than black smoke.
It’s not necessarily black smoke is always have to dangerous. A burst of smoke is sometimes all it takes.
There are, however, potential risks associated with black smoke and that’s why mechanics recommend keeping an eye on it.
Catalytic converters are a crucial component in a car’s engine. They help prevent harmful pollutants from entering the environment. However, black smoke in catalytic converters is a major problem for car owners.
Carbon monoxide is an odorless gas that can harm the human body. It can cause headaches, nausea, fatigue, dizziness and breathing problems.
Why Does a Catalytic Converter Emit Black Smoke?
The reason why black smoke is coming out of your car’s exhaust pipe is the presence of carbon monoxide in the engine. When the engine is running, carbon monoxide is formed when fuel is burned.
If the fuel and oil are in proportional amounts, over burning fuel, combustion of fuel. Basically, in the combustion process air and fuel mix together, it produces black smoke.
There are a number of factors that can contribute to catalytic converter producing black smoke. These include:
1. Incorrect Air/Fuel Mixture
An incorrect mixture of air and fuel can cause the engine to run lean. Catalytic converters are incapable of functioning if the mixture is too rich.
2. Poor Quality Fuel
The catalytic converter can produce black smoke if the fuel is of poor quality. Poor quality fuel can be a result of several different issues. Such as-
- A poorly designed engine.
- Improper fuel injection.
- Low-quality gasoline.
- Too much oil in the fuel.
- Low octane fuel.
3. Improper Maintenance
The catalytic converter can produce black smoke if it is not properly maintained. For example, if the catalytic converter is not cleaned regularly, it can lead to carbon deposits and rust.
Learn more: How to clean black exhaust tips?
How to Prevent Catalytic Converter Producing Black Smoke?
You can prevent catalytic converter from producing black smoke is by-
- Maintaining the proper fuel and oil ratio.
- Regularly maintaining a catalytic converter.
- Checking occasionally the cat back system and cats in the mechanic shop.
The main cult of black smoke in catalytic converters is mix of air and fuel in the combustion process. And, it happens when you use low grease octane and improper mix of oil and fuel. Just by checking this, you can reduce black smoke drastically.
Wrap Up
People are often fooled by the black smoke by not paying enough attention to it. Black smoke, however, can sometimes lead to some dangerous consequences. That’s why you need to carefully watch out for the black smoke.
Throughout the post, I showed what black smoke in a catalytic converter means, why it’s produced and how to prevent it.
A professional tip I can give you is to take your vehicle to the repair shop once in a while.