Car Runs Rough After Fuel Injector Cleaner [5 Easy Solutions] 

Car runs rough after fuel injector cleaner! Many car owners experience this issue when they change their oil and add a bottle of injector cleaner into the fuel injection system.

Actually, a fuel injector causes no problem if you use it correctly. But if you use it incorrectly, you will experience roughness or your car will hesitate a little bit on acceleration. 

Your car will run rough after using a fuel injector cleaner for several reasons. Dirty fuel filters, putting incompatible injector cleaners, or the injector cleaner cleaning the fuel lines are some culprits responsible for a rough-running car.

Below, we will break down each of them. Apart from these, we will also describe: 

  • Can fuel injector cleaner cause problems?
  • How to use injector cleaner correctly to avoid potential damage?

Without further ado, let’s dive in. 

Car Runs Rough After Fuel Injector Cleaner [5 Easy Solutions]

Don’t know why you experience some roughness after using a bottle of fuel injector cleaner?

fuel injector cleaner

Then, continue to read to know the underlying reasons behind this issue. 

1. Dirty Fuel Filter

The main culprit behind a car running rough is the dirty fuel filter. If your car runs rough after putting fuel injector cleaner, inspect the fuel filter first.

It will cause an excessive amount of fuel to go into your car engine if the fuel filter gets dirty. 

We recommend you replace the fuel filter in the first place to avoid the issue of a rough car running.

Alternatively, you can buy a fuel injector that can release the dirt & debris out of your fuel filter. In this case, you can use a Techron or Redline injector cleaner to do this task. 

2. Maybe Your Car Injector Types Don’t Like The Cleaner

Not every injector type of your car will be compatible with certain types of injector cleaners. So, instead of doing better, they damage the fuel injector. That’s why you can expect a little stumbling as the cleaner removes the varnishes of carbon and forces the buildup to go through the injectors. 

To avoid the roughness of your car, you can use an injector cleaner that is friendly to every injector type. Regarding this, you can go for the Redline injector cleaner. Just add a little bit of Redline with each tank of fuel. It helps remove carbon deposits over time if you apply the injector cleaner this way. Sometimes the roughness of your can will reduce as the tank gets empty. 

3. Injector Cleaner Cleans The Fuel Lines

You can think of the injector cleaner as a solvent. It dissolves the dirt and debris captured by the fuel filter. Besides washing away the dirt & dust buildups, it also cleans the fuel lines and the bottom of your tank. 

Consequently, the dirt and water it lifts will get trapped in the filter, which causes fuel flow problems. Due to this reason, your car will hesitate on acceleration or the idle goes up and down. 

The only way you can tackle this issue is to change the fuel filter after one or two tanks of fuel. 

4. Your Car May Have Multec Injector

Some cars like the 1989 GM have Multec Injector. Such an injector has a ball design, unlike the Bosch-style injector. It means the ball continuously rotates to remove the buildup and gives the injector a different seating surface. 

Generally, the Multec Injector is designed to let the fuel flow over the coils of the injector to keep the coils cool.

If you use an injector cleaner that contains chemicals, the cleaner can corrode the protective coating on the coils and damage the injector in the process. In short, it causes the injector to fail.   

The best suggestion we can give you is to check the resistance of each injector. Just grab an ohmmeter and inspect the injector, The resistance of the injector should be between 11 to 16 ohms. Otherwise, you should replace the injector to avoid car roughness. 

5. Maybe You Add Too Much Injector Cleaner

Adding an excessive amount of injector cleaner can cause damage. Keep in mind, that injector cleaner can’t bring any harmful effects to your vehicle if you use it correctly.

But when you put a lot of it, it will show its negative effects. For example, it will damage the fuel tank lining if you use too much injector cleaner. On top of this, it may also impact the lubricity and efficiency of your vehicle. 

To avoid this adverse effect of putting in extra injector cleaners, we recommend you use them while maintaining the package instructions.

Add 2 ounces per gallon if you want to use it as a cleaner. But you should add only 1 ounce per gallon if you wish to use the injector cleaner regularly. 

Can Fuel Injector Cleaner Cause Problems?

Typically, fuel injector cleaner causes no issues in most cases. Most products advertised as injector cleaners contain enough solvent to call them a solvent. However, many of them don’t clean too much.

Of course, you can find some good products but you need to pay a little more to get them. Those injector cleaners may cause damage if you use them incorrectly. But, it’s very rare. 

We did a lot of injector balance tests on several cars and put high-quality injector cleaners (like Redline) through them. Believe it or not, we noticed a dramatic improvement after using the cleaners.

However, we recommend you wait until you get down to less than a quarter tank of gas before putting the injector cleaner. 

However, some injector cleaners like GM engine cleaner are the strongest type of cleaner we ever used. If you use it incorrectly, it will cause a lot of damage including fuel pump damage, sensor damage, and excessive vibration. 

In short, in every rare case, an injector cleaner can cause damage. But in most cases, it helps you clean your engine if you use it correctly. 

How To Use Injector Cleaner Correctly To Avoid Potential Issues?

Every injector cleaner is beneficial for your engine if you use it properly. Below, we will show you how to use this cleaner correctly. So, keep scrolling. 

Consider The Engine Type

Before getting an injector cleaner, first, take your engine type into account. Some engines run on petrol and some of them run on diesel.

Ensure the injector cleaner you are going to pick is compatible with your engine. Otherwise, it will bring untold damage to your engine.

For example, the engine cleaner made for diesel engines contains strong chemicals to clean carbon deposits. If you use this injector cleaner in your petrol engine, it will surely damage your engine. 

Use The Right Amount Of The Cleaner

Once you choose the appropriate injector cleaner, it’s time to determine how much engine cleaner your vehicle needs. Adding too much cleaner will cause damage and putting a too low amount of the cleaner will bring unsatisfying results. 

The rule of thumb is- that you should add an ounce of the cleaner per gallon of the vehicle’s gas tank capacity. In other words, you should add 10 ounces of the injector cleaner if your car can hold up to 10 gallons of gas. 

It Contains PEA Or Not

Lastly, check whether the injector cleaner you pick contains PEA or not. Those injectors that have PEA or polyether amine can effectively clean the fuel injection system.

This type of injector cleaner can also loosen & dissolve carbon deposits to maximize overall engine performance.


How long does it take for a fuel injector cleaner to kick in?

It starts working when you put fuel injector cleaner. But you can notice the significant result of adding this engine cleaner within 100-300 miles after using the injector cleaner. 

Can A Fuel Injector Cleaner Cause A Misfire?

Eventually, a fuel injector cleaner causes no misfire. It actually prevents the misfire as it cleans the fuel injector system. Therefore, it also loosens and eliminates carbon buildup on your car cylinders to improve overall performance.

Does fuel injector cleaner clean spark plugs?

Unfortunately, a fuel injector cleaner can’t clean the spark plugs. So, if you purchase fuel injector to clean the spark plugs, it will be just a waste of your money. 

Does fuel injector cleaner work?

Yes, fuel injector cleaners work like a champ. They will help you remove carbon buildup if you use the injector cleaner regularly. 

Does fuel injector cleaner clean the o2 sensor?

No, fuel injector cleaners can’t clean the O2 sensor. 


The car will run rough after putting fuel injector cleaner if the fuel filter is dirty or you put the wrong type of injector. Fortunately, we mentioned above what you need to do in this case.

If you follow those guidelines, you will never experience or encounter this issue. We also broke down how to use the injector cleaner correctly so that you can avoid the same problem in the future. If you still have a lot of questions to ask, check out the FAQs section. 

About John M

John contributed as a technical head at an automobile company just 2 years after his post-graduation in Automobile Engineering. He loves to lead a free life, so he left his job & started blogging. Now, he does research on every automotive problem, part & product and seeks a better solution & best products & shares his findings with his readers to help them as well as to minimize their struggle.

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