Can Bad Gas Cause Check Engine Light? (Quick Answers)

Nobody wants their vehicles’ check engine light to illuminate, right? It usually means that there is some issue with the engine and it needs servicing as soon as possible.

A check engine light can turn on for various reasons. You might be wondering if poor quality fuel can cause a check engine light. Let’s find out if bad gas can cause check engine light.

Can bad gas cause check engine light?

A poor quality gas can cause the check engine light to illuminate because the fuel will detonate during compression in the internal combustion engine. Bad gas will also have a high impurity level and rough texture, which will cause the engine to malfunction and turn on the check engine light.

The fuel is the most important component of a car. Without gas, a car won’t even start let alone run. If the quality of the fuel you use in your car is not up to the mark, the car will face various issues. One of those issues will be the illumination of the check engine light.

The check engine light will come on for poor quality fuel due to various reasons. To prevent permanent damage to your engine you should address the issue as soon as possible when the check engine light comes on.

The low-quality fuel is not properly refined and remains dirty. So, the impurity level of the bad gas will be higher than what the engine and fuel filter can withstand and filter out. As a result, there will be a hindrance in the mechanism of the engine and it will malfunction, causing the check engine light to come off.

A vehicle’s engine prefers smooth textured fuel. This is due to the fact that the engine requires less power to combust the smooth fuel as it is easier to combust. The texture of the bad quality gas is very rough, as a result, the engine won’t be able to ignite all of it effectively. A good amount of fuel will remain unburnt due to this, which will illuminate the check engine light.

The octane level of the bad gas is fairly low. It cannot withstand pressure in an internal combustion engine without blowing up. So, if you use a bad quality fuel, it will blow up in the engine and activate the check engine light.

How long does it take for bad gas to cause check engine light?

The number of days it will take a bad gas to check engine light varies from car to car. Usually, it takes around two to four weeks for poor quality fuel to activate the check engine light.

After almost 20 to 30 days of sitting in your car’s fuel tank, the bad fuel begins to oxidize. When gas oxidizes, it can clog your fuel system by converting it to varnish. The varnish will coat your vehicle’s fuel system and engine and will cause the engine check light to illuminate.

That being said, if the quality of the fuel is so bad that the engine isn’t able to ignite it at all, the check engine light will turn on immediately. In this case, the time required for the check engine light to turn on is about an hour.

3 reasons why bad gas causes check engine light

There are 3 significant reasons why bad gas can cause the check engine light to turn on. It is very important to know and understand the reasons so that you can fix the issues immediately after the check engine light turns on.

Have a look at the reasons for which poor-quality gas causes check engine light:

Low octane rating:

The octane rating of the bad gas is quite low. As a result, the fuel will detonate when pressure is applied to it while igniting the gas in the engine. When the fuel blow up inside the engine, it won’t be able to ignite the fuel, causing massive misfires. Due to the misfiring engine, the check engine light will illuminate.

High impurity level:

Since a poor quality gas is not properly refined, its impurity level is very high. The high impurity level is caused by various natural components and materials. The fuel filters can’t filter out the impurity above a certain level.

If the pollutants enter the engine, it will not function properly and frequently misfire. So, the high impurity will make the engine malfunction and the check engine light will turn on.

Rough texture:

The texture of the bad quality gas is not smooth at all. Due to the rough texture of the gas, the pistons of the engine will get worn out in a short period of time, causing the engine to malfunction. When the pistons start to decay, the check engine light lights up to prevent any further damage.

How to know if bad gas caused check engine light code?

Knowing if bad gas really caused the check engine light code in your car is not that complicated. One of the easiest ways to know it is by bringing the car to a car mechanic and having the code read.

If your check engine light illuminates after a while of refueling the car, you should refuel the car with premium fuel from some other gas pump. If the check engine light code trunks off after refueling the car with a tank or two of good fuel, it means that this code was activated due to bad fuel.

What are the symptoms of bad gas in your car?

There are numerous symptoms of bad gas in your car that is causing the check engine light to turn on. The symptoms include damaged fuel tank, struggle to start, the car stalls, and more. It is necessary to know what the symptoms are so that you can address the issue immediately after detecting the signs.

Let’s take a look at the symptoms of bad gas in your car.

The car struggles to start:

The first and most major symptom of bad gas in your car is that it will struggle to start. This occurs because with poor quality fuel the engine won’t be able to ignite the fuel properly to start the car. The octane rating of the bad gas is also very low as a result it detonates while pressure is applied, preventing the car from starting smoothly.

Damaged fuel tank:

The bad quality gas has numerous impurities and the texture is not smooth. When this gas is kept in the fuel tank, it will start to corrode and decay after a certain period of time. So, if your car has a damaged fuel tank without any exterior damage, it is surely due to the bad gas.

Car stalls and engine misfires:

If your car suddenly stalls and hardly moves, it is a sign that the quality of the gas is bad. You should check the quality of the fuel immediately if it happens. The car’s engine can also frequently misfire due to bad gas.

How to treat bad gas in a car?

Treating bad gas in a car is not as complicated as it may seem to you at first. You can do it with a little bit of effort and time. However, you need to do it in the right way to prevent any damages to the vehicle.

Let’s find out how you can treat bad gas in a car.

Clean the tank:

One of the easiest ways to treat bad gas in a car is to get all the poor quality fuel out of the car. You can do it by emptying the fuel tank and then cleaning it thoroughly. After that, use premium fuel in the car to reduce the pressure in the engine and treat the remaining bad gas in the engine shaft.

Clean fuel line:

The fuel line basically supplies fuel to the engine and produces power. If there is bad gas in your car, it will get clogged in the fuel line. So, to treat the bad fuel, you should clean the fuel line.

Change fuel tank:

If you have used bad gas in your car for a long period of time, the fuel tank will get damaged. To treat the bad fuel, you will have to change the fuel tank. Otherwise, you won’t be able to treat the fuel even with premium fuel.

Final Thoughts

Bad gas will surely cause the check engine light to turn on. This occurs because the bad fuel detonates when pressure is applied to it during combustion within the engine. The check engine light will also illuminate because there are a lot of impurities in bad gas which will cause engine misfire.