Cracking The “Flames From Exhaust” Mystery

If you’ve ever heard a loud pop and witnessed flames ejecting from the tailpipe of a vehicle, you were probably mesmerized and a bit scared for the vehicle at the same time.

It’s natural to worry about a car that spits flames from its exhaust, don’t worry, though; the car isn’t about to explode or anything.

Whether at a car show, on a race track, or just cruising down the highway, there are plenty of fast cars, as well as drag cars that spit out fire when they drive.

Once you understand why cars eject flames from the exhaust, you’ll realize exactly what’s happening next time you see a fiery car in a race or moving down the road. 

Why Cars Spit Flames from their Exhaust

There’s a simple explanation for why cars spit flames out of their exhaust pipes, and that’s because the cars have an excess of fuel during internal combustion.

This leads to a larger combustion event than what the engine is designed for, and that’s when flames can burst out of the tailpipe and into the air behind the vehicle. 

How Internal Combustion Works

An internal combustion engine is on most modern cars today. Engines that use internal combustion mix together fuel vapor and oxygen inside pistons and use a spark to ignite the mixture.

When the mixture ignites, it sets off a powerful explosion that generates a huge amount of power. The power is harnessed to spin the wheels and move the vehicle down the road. 

The fact that internal combustion relies on contained explosions is also what leads to fire shooting out of the exhaust pipe of a vehicle when it’s running improperly. The flames come from issues with that combustion process that so many people rely on today. 

Where Do the Flames Come From?

If flames shoot out of your car’s exhaust, they are caused by combustion that isn’t contained in the cylinders of the engine as it’s meant to be.

Instead, combustion spreads out of the cylinders and down through the exhaust system. The more excess fuel vapor there is to combust, the greater the flame that emits from the rear of the vehicle. 

There is a limit to how much fire can be generated, though, and when enough fuel vapor is present, some of it will leave from the tailpipe without combusting. 

More Common in Carbureted Engines

It’s much more common for fire to be ejected from the exhaust pipes of a vehicle that comes equipped with a carburetor. This is because the fuel and air mixture is flowing close to the cylinder of the engine.

This can lead to larger combustions and serious backfiring from the tailpipe when the circumstances are just right. 

If your vehicle relies on fuel injection instead, it is less likely for backfiring to occur. The technology helps protect against the issue and can help reduce the problems with an increase in fuel consumption as well. 

Rotary Engines Create Flames Readily

While it’s possible to get many vehicles to emit flames with some adjustments in the way you drive, the type of fuel you use, and the construction of your exhaust system, some vehicles are more prone to this issue than others. Rotary engines are known for running richly or using more fuel than necessary.

They’re highly inefficient compared to the modern internal combustion engines used on most vehicles today. By equipping your vehicle with a rotary engine, you’ll greatly increase your chances that your car will spit fire.

You can take things even further by removing the catalytic converter and straight piping your exhaust system. 

Less Restrictive Exhaust Systems

Catalytic converters work to convert excess fuel vapor into safer compounds that won’t combust. Most modern vehicles are required to have these exhaust components, but some older vehicles do not.

There are also car owners that remove the catalytic converters in the quest for performance gains by creating a less restrictive exhaust system.

It’s not recommended to get rid of the catalytic converter on your vehicle, but if you do, you’ll have a greater chance for your car to shoot flames out its tailpipe during use.

This is the main reason that some drag cars emit flames during use. When a car is optimized to create the highest level of performance, it might spit out slight flames during use. 

These changes are horrible for the environment and will likely make the vehicle illegal in your area, but the car will likely spit fire after the changes are made. 

Signs the Engine is Running Rich

Besides the loud bang and flames ejecting from the tailpipe of your vehicle, there are other signs your vehicle has more fuel than it needs during combustion.

It’s common for the exhaust pipes to be sooty and for the spark plugs to become dirty when a fuel-heavy mixture is used for combustion.

The vehicle may also vibrate more than usual, and it will suffer from poor fuel economy.

If your vehicle has these issues, you’re likely burning more fuel than necessary during combustion, and things could be optimized. 

Are Exhaust Flames Dangerous?

Even though the fiery exhaust isn’t bad for the engine in your vehicle, there are some other issues you may have to be concerned about depending on your emissions system.

The flames that erupt out of the car don’t do any damage to the engine, but they can harm the exhaust system. In fact, some cars’ backfiring can cause the exhaust system to fail completely. 

If your car is backfiring with flames frequently, you’ll need a stronger exhaust system to withstand these extreme conditions.

Many performance cars are already enhanced to protect against this issue, especially drag cars and other vehicles built to output as much power as possible. 

Why Your Car Might Be Running Rich

While it’s unlikely for a modern fuel-injected car to suffer from backfiring that emits actual flames if you notice any issues with backfiring, you’re probably wasting a large amount of fuel each time you drive. 

A Faulty MAF Sensor

The MAF sensor is tasked with detecting how much air is reaching the engine. If this sensor takes an improper reading, it will either tell the car to put in too much or too little fuel.

A problem with the MAF sensor is the most likely reason your vehicle is running rich and could lead to backfiring in some instances. 

A Failing O2 Sensor

The O2 sensor in your vehicle monitors the exhaust exiting your vehicle and tells the vehicle’s computer when too much oxygen is left in the exhaust at the end.

If the sensor is faulty, it could tell the engine to inject more fuel when it doesn’t need to. This can lead to serious fuel inefficiencies and even backfiring in some extreme cases.

These sensors are simple to replace, and they should be verified by a mechanic if you believe they’re faulty. 

A Faulty Coolant Temperature Sensor

The engine has a special sensor that checks the temperature of the engine coolant to determine how warm the engine is.

When the engine is colder, the oxygen within is condensed, and more fuel is required to achieve proper combustion.

If the sensor is faulty and it tells the computer the engine coolant is far colder than it is, the engine may receive more fuel than it needs during operation.

This leads to rich performance and some potential backfiring as well. 

A Damaged Fuel Pressure Regulator

The fuel pressure regulator informs the fuel pump how hard it should work to maintain the right fuel pressure for the engine to operate properly.

If the sensor goes bad, it’s possible the fuel pressure will get higher than necessary. If that happens, your engine will start getting more fuel than it needs. 

Each of these different issues can cause your engine to run richer than necessary, and each should be diagnosed if you notice problems with your engine.

Running rich isn’t horrible for your engine, but it can cause damage to your vehicle’s exhaust system eventually. You’ll also go through more fuel than necessary when your vehicle is operating inefficiently. 

Even if it’s a dream of yours to have a car that shoots flames, it’s important to realize that these vehicles aren’t efficient, they are mildly dangerous when modified improperly, and they’re not practical.


When you understand all the reasons a car might shoot flames, you can appreciate what’s making this happen, and you can understand why it isn’t practical for your vehicle to shoot flames. 

Many performance car owners dream of making their vehicles shoot out flames. These same car owners also want to keep their vehicles looking great and to help them stand out wherever they go.

These owners work hard to keep their vehicles clean, which means frequent washing. Washing a vehicle is time-consuming and hard work for most.

It doesn’t have to be inconvenient to keep your vehicle in excellent condition, though.

No-H20 offers a mobile car washing service that allows you to have your vehicle washed at your home, at the office, or anywhere you are. Work with the company and keep your vehicle clean easily.

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