12 Common Problems after Fuel Injection Cleaning

When it comes to modern vehicles being clean and safe, fuel injection is one of the most important parts. They play a crucial role in making sure that you get the power that you need, as well as helping your car run smoother than ever.

However, many drivers still have issues with their fuel injection systems after cleaning for some reason or another. It is a widespread problem, but there are ways that you can go about fixing it. This blog post explains the most common problems after fuel injection cleaning.

Problems after Fuel Injection Cleaning

With so many fuel injection systems requiring constant maintenance, it is no wonder that most of them need cleaning every once in a while. However, cleaning your fuel injection system will take a toll on it, and if you do not use the right cleaner, there are certain risks to consider. These risks include the following:

1. The Check Engine Light Turns On

One of the most common problems after fuel injection cleaning is the check engine light turning on. It can turn on for various reasons, but it’s important to know that it’s important not to panic if you ever see this light start flashing.

The best thing for you to do is get your car looked at by a professional, who can find out easily enough if there are any real issues present or not.

For example, one problem that would cause the light to come on could be a loose gas cap. If a gas cap is loose and unable to seal properly, fuel can leak.

Not only that, but too much air in the tank will also cause problems like this. The solution for this would be to replace the cap to seal properly.

2. Your Car Runs Slower than Usual

Another common issue is that your car runs slower than it should after fuel injection cleaning.

If you’re experiencing this problem, then it’s likely that a clog somewhere in the system is causing this to happen.

You can’t always tell exactly where the clog is from the outside, but if you have a professional look at your car, they should be able to tell what’s wrong on their own.

It could simply be a clogged or stuck fuel injector (if any) or perhaps a clogged or dirty fuel filter. Whatever it is, it’s high in the recommendation to get this checked out.

3. Your Car Doesn’t Start

A common problem that you will see after fuel injection cleaning is that the engine does not start.

It may sound a little strange, but if you look around, you will realize that many people have this problem after their car gets cleaned.

The reason is that the check engine light may come on, causing the car not to start. If you’re experiencing this problem, I recommend checking out your check engine light.

Many people forget that lights like these can flash for reasons other than an actual problem.

4. Your Car Idles Very Poorly

Another common problem that you may have after fuel injection cleaning is that the car idles poorly. In this case, it’s a good idea to look at the throttle position sensors.

They can be damaged if the car is revving for an extended period during the cleaning. Another problem that could cause this not to work properly anymore is oil or dirt build-up in them.

5. Your Car Has a Knock

Some cars will have a knocking sound when they’re idling. It is why it’s important to pay attention to everything your mechanic does and how your car is performing before you leave.

If you leave with any problems, then they will not be able to fix any other issues that might arise later on.

6. You Need a New Throttle Body

One of the most common reasons for mass failure from fuel injection cleaning is that a new throttle body is required. It often occurs because the old one has developed cracks or other problems.

They can also be damaged if there’s dirt or other debris in the system. Some people don’t know that this is a common problem, and they shut off the car and ask for their money back. They don’t think that there could be something wrong with their car.

7. There Are Problems with Your Fuel Tank

Many people have trouble after fuel injection cleaning because there are problems with the fuel tank.

More than 90% of people who complain about damaged injection systems in their cars have problems with the gas tank.

8. Your Fuel Filter Is Clogged

Another common problem is that your fuel filter is clogged. It’s is in the fuel tank, and it filters out leftover dirt and other contaminants that may be there.

When this happens, some cars can’t get enough fuel to the engine, which means you can’t drive anywhere. You have to replace it as soon as you notice it isn’t working properly anymore.

9. You Need New Oxygen Sensors

One of the most common issues that you’ll find after fuel injection cleaning is that new oxygen sensors are required. If there are any clogs in the injection system, it can’t function properly.

The oxygen sensors read this and signal the engine to increase or decrease its power. It’s in the recommendation that you replace these as soon as possible.

10. Your Car’s Performance Decreases

Another common problem after fuel injection cleaning is that your vehicle’s performance decreases. It could be due to several reasons, such as clogged or dirty gas filters, damaged or worn throttle bodies, defective sensors and bypass valves, causing poor engine performance, or plug wires not being strung properly.

Another problem that could cause this is a leaking valve seat, making it hard to start.

11. There Are Problems with Your Ignition System

Another common problem after fuel injection cleaning is problems with the ignition system. It happens because people often don’t clean out the entire system or don’t properly clean out the fuel injectors.

If they don’t clean out everything in the system, then the dirt will build upon other parts and cause them not to work properly.

12. Your Catalytic Converter Is Damaged

Another reason you may have trouble after fuel injection cleaning is that your catalytic converter is damaged. It can happen because the engine doesn’t run as efficiently as it used to, which can cause damage to the converter.

If you don’t drive your car after getting the cleaning done, this can also happen.


Fuel injection cleaning can cause some major problems with your car, but it’s also highly recommended. It can be a beneficial procedure if you know what to expect before and after it. That’s why it’s important to research everything you can before getting this done to make sure it is necessary and that you don’t have any problems afterward.

  • Eric Williams

    I'm the founder of Daily Car Tips. I wrote articles in the automotive industry for more than 10 years, published in USA and Europe. I love sharing my knowledge and insights with fellow enthusiasts. Join me on this journey as we explore the exciting world of cars together!

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