Is your car sputtering and at the same time the check engine light is on? Are you wondering what this means and how to solve the issue? If yes, we’ve put together this detailed guide to help you out.
Check engine light car sputtering is telling you that your car engine is experiencing a serious issue that requires immediate action before it develops into expensive repairs. Have your mechanic diagnose the source of the sputter as soon as possible and fix it early enough.
In this guide, we’ve discussed more details on why your car engine is sputtering and the check engine is illuminating at the same time. We have also discussed how to solve this issue so that your car continues running like it’s new.
Why your check engine light is one and car is sputtering
Typically, the check engine light turning on (and is blinking/flashing), it indicates that your vehicle engine is misfiring. And this would explain why you’re getting sputtering as an additional symptom.
Probably the most common reason for engine to sputter is lack of fuel. But the source of the sputtering can also be traced to different other parts of the car engine system.
Here are the most common causes of your car engine sputtering and check engine light coming on:
Failing catalytic converter
Failing catalytic converter is another potential cause for engine sputtering. This is usually followed by additional symptoms such as rough running and rotten eggs smell.
A check engine light will also come on in most cases. With time, the cat converter will become totally blocked and your car may not even start.
Faulty oxygen sensors
The malfunctioning of Oxygen sensor can also result in engine sputtering and check engine light coming on.
The work of O2 sensor is to measure how lean or rich exhaust gases are when leaving the combustion chamber. The car computer then uses this info to adjust the amount of fuel that enters the engine.
When the sensor is dirty or faulty, it will put too little or too much fuel in the engine, making it sputter or run rough.
Exhaust manifold leak
Exhaust manifold collects exhaust gases and a leak in it will cause the engine to sputter and even run unevenly.
Additional symptoms of this condition include poor engine performance, increased engine noise, and the check engine light coming on.
A leaking or cracked manifold leak can be dangerous given that escaping hot gases will melt any nearby plastic components. The exhaust fumes may also find their way into your car cabin.
Dirty fuel injectors
When was the last time you had your fuel injectors cleaned? Can’t remember? Well, dirty fuel injectors could be the reason behind sputtering and CEL illuminating.
The injectors simply spray fuel into the cylinders. And when their nozzles become clogged, the engine starts sputtering, acceleration becomes slow, and your car will not have enough power.
Good news is that you can clean the fuel injectors if you catch the problem early enough. But if the condition worsens, you’ll have no other option but to replace them.
Dirty mass airflow sensor
The mass airflow sensor is responsible for measuring the amount of air entering fuel injection system.
It sends this crucial info to your car computer, which then transmits the right quantity of fuel to the combustion chamber.
A dirty MAF sensor will send incorrect info to the computer, causing rough running and sputtering engine.
Bad spark plugs
Spark plugs are tasked with igniting fuel in the combustion chamber. If they become dirty or can’t work properly, they’re unable to cleanly ignite the fuel and your car engine starts misfiring or sputtering.
Cleaning or replacing dirty of bad spark plugs respectively is the best solution here.
A leak in vacuum system leak can also cause sputtering and even rough running of the engine. As the problems continued developing, your vehicle may even stall or hesitate when you try to accelerate it.
As you can see, there are many possible causes for engine sputtering and check engine light illuminating.
Any of these causes is capable of developing into more critical problems to your car engine, which is why we recommend taking immediate action and having your car diagnosed for the problem.
What to do if your car sputters and check engine light is on?
If your check engine light comes on and car starts sputtering, you should have the trouble codes retrieved. This will help with diagnosing the car and finding what fault caused the check engine light to come on.
Without the codes, it would be impossible to diagnose your car (especially given the fact that the CEL is on). The error codes will help point you into components that are problematic and make it easier to find out what problem your engine is going through.
A reputable auto repair shop will also inspect your car exhaust system and other important components including the oxygen sensors, exhaust seals and gaskets, exhaust manifold, airflow sensors, and more.
Sometimes the mechanic may also crank up your car to diagnose the sputtering noise.
Afterward, they’ll provide you with a detailed report of what caused the CEL to come on and the engine to illuminate. The report will also include the scope and cost of all the repairs needed to fix the issue.
Why is my car sputtering and check engine light flashing?
If your car is sputtering and at the same time the check engine light is flashing, you have an engine misfire.
When this happens, you’ll need to check why your check engine light is flushing and the engine sputtering.
Get a certified mechanic to inspect the car ignition system and diagnose the sputtering problem to find out the issue that triggered the engine warning light.
A professional mechanic will inspect the ignition coils, spark plugs, and all the wiring connecting these two parts. In most cases, faulty spark plugs or bad ignition coils are always the problem.
If only one spark plug is causing the misfire, you’ll need to replace all of them as good maintenance practice.
If you have faulty ignition coil, you can just replace one as each spark plug has its own ignition coil in the engine, and it does affect the other cylinders.
Why is my car sputtering while idling and check engine light is on?
In a case where your car engine is sputtering when idle, it could be a sensor problem or an engine misfire. The fact that the check engine light is on it means your car computer is sensing a problem with the engine.
You should consider having your car computer diagnosed for codes to give you a starting point as to what problems the engine is going through.
Remember, the sputtering at idle could be one of the first symptoms to a deeper problem, so the earlier you take action the better.
If your car has additional symptoms apart from sputtering while idle, your engine may have even more severe problems.
Bottom line: As long as the check engine light has illuminated at the same time the car is sputtering while idle, it means your car has a problem and you should take it to a mechanic for check engine light diagnostic test as soon as possible.
Why is my car sputtering when I try to accelerate?
Your car is sputtering when you try to accelerate to alert you of an underlying issue that needs to be resolved as soon as possible before it develops into a more serious problem.
The most common issue for engine sputtering is when you’re low on fuel. However, this is less likely to happen as most car owners recognize when they’re low on gas. But you may still want to check if it’s the cause for your engine to sputter.
The other likely causes for this problem include a clogged mass airflow sensor, clogged catalytic converter, bad spark plugs, clogged air or fuel filter, malfunctioning oxygen sensor, malfunctioning fuel pump, vacuum hose leak, etc.
When your engine sputters whenever you try to accelerate, take your car to the mechanic as soon as possible. They’ll inspect the engine and find what causes the sputtering problem.
Why is my car sputtering after I changed the spark plugs?
A car sputtering after spark plug change is common. If you installed the spark plugs incorrectly, with the wrong gapping, or the wires are worn or lose or incorrectly hooked, engine misses will happen and make the sparks misfire. Rough idling or sputtering may also occur.
Double-check the spark plugs gapping and use new wires for the plugs whenever you do tune ups.
The sputtering could also be happening during the break-in period for the spark plugs. You may not know this but spark plugs feature anti-corrosion coating on the electrode.
After installation, the spark plugs will need to go through a break-in period to help clear fouling likely to occur, including the lubricant that some mechanics apply on the threads.If your car is sputtering, it could be a sign of a problem with the engine, fuel system, or ignition system. In some cases, this issue could also be associated with other common problems, such as a flashing then solid check engine light or flashing stops accelerating. To learn more about these potential causes and what you can do to fix them, check out our articles on flashing then solid check engine light and flashing stops accelerating. These articles provide helpful tips and insights on how to troubleshoot and solve these issues, so you can ensure the safety and reliability of your vehicle and prevent any further damage.
Frequently Asked Questions
It depends with the level of sputtering the engine is exhibiting. If the sputtering is mild, it is okay to ignore it for some time but you should still have it checked by an expert. For extreme sputtering, you should consider towing your car to the mechanic right away to avoid damaging engine components and paying heavily in repairs. If the check engine light is flashing and the car sputtering, you should also not ignore.
The MOST common cause for car to sputter is lack of fuel. But if your car still sputters and the fuel tank is full, it is indication that there are other problems your car engine is experiencing. These issues include faulty oxygen sensor, vacuum leak, faulty spark plugs, faulty ignition coils, dirty fuel injectors, failing catalytic converter, failing mass airflow sensor, or even bad gaskets and seals.
Whenever your car engine starts sputtering check engine light comes on, it is an indication of a deeper problem the car engine is going through. If this issue isn’t diagnosed and repaired on time, your car will most likely start stalling and even give you a hard starting it. Eventually, it may stop running altogether.
With the check engine light illuminating, it means there are fault codes in the car computer. Have your vehicle computer scanned by your mechanic for the trouble codes to give you a starting point as to what problem is. The mechanic will also inspect key parts of the car to help find the issue and suggest the bets repairs to fix the underlying issue.