- Written ByJohn Goreham
- 5/10/2024
Edited ByJulie Bausch Lent
One controversial vehicle maintenance procedure is fuel injector cleaning, also called fuel injector service. This is a maintenance procedure sometimes recommended by repair chains, independent shops, and dealers but seldom listed in vehicle owner’s manual. This is a service often combined with throttle body cleaning, which is also not a recommended maintenance procedure listed in service manuals.
You may be at a new shop where you have not previously had your car serviced, and the service advisor is recommending this to you. Based on our research, the price is usually between $150 and $200, and when combined with a throttle body cleanout, it may have a bundled price of around $250 or $300.
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Should you have your fuel injection system cleaned?
The first question is, “Should you have this service performed?” To answer this, we will, in turn, ask our readers a question: “What problem is this intended to solve?” If your vehicle is running poorly, has a check engine light illuminated, or your owner’s manual (not to be confused with a dealer’s list of recommended services) says to do this job, we won't argue with the shop telling you that it is needed. But if none of these qualifiers are satisfied, we can’t imagine what benefit this will have.
Why shops say you need fuel injector cleaning service
Shops will often have a good reason (imaginary) why you need to perform a fuel injector service. They may even have a poster to point to, supplied by their fuel injector service chemical supplier, of course. The argument goes something like, ‘Your gas is dirty and will eventually clog up your injectors.”
We have two things to say about that.
First, no, your gasoline is not dirty if you use name-brand or “Top-Tier” gasoline. And discount gas may also be quite clean. In fact, gasoline has detergent in it, specifically intended to prevent fuel system buildup of any kind. You don't need to buy Premium to get this detergent. Top-Tier gas suppliers agree to include the same level of detergent in the 87-octane fuel as they do in the overpriced and unnecessary Premium.
Second, so what if your injectors become clogged? Your car will tell you this with a check engine light, and you can then take action. The car won’t suddenly screech to a stop. It’s just not a thing that occurs in the real world.
Image is courtesy of Mazda’s 2018 CX-5 Manual
Some brands’ owners manuals specifically warn you not to use fuel system cleaning additives
One way some shops “clean” injectors is by adding a bottle of solvent they pay $3 for and charge you $50 for. Not only is this stuff unnecessary, but it may also harm your engine’s emission control system. Mazda is one brand that has a section in its maintenance manual that warns owners not to use any fuel system cleaning additives. Don’t take our word for it, take Mazda’s. Fuel system additives are just one of many snake oils chemical companies are dying to sell you that may do no good and may actually do harm.
How do shops clean injectors?
There is more than one type of fuel injection and more than one type of way to clean injectors. In some cases, the shop will hook up a machine to the engine’s fuel injection system and introduce harsh chemicals to the injectors under pressure. In other cases, the injectors are “cleaned” by adding the above-mentioned snake oil. It’s hard to say which method is better without knowing a real problem existed before the supposed cleaning.
Can I clean my own fuel injectors?
Modern fuel delivery systems are under high pressure. Working on them is risky for many reasons, including fire and contamination. We do not advise inexperienced vehicle owners to work on any part of their fuel delivery system at home. Now, back to the bigger question: Why in the world would you be cleaning a fuel injection system in the first place? This is not a routine maintenance item for mainstream vehicles.
The bottom line on fuel injector cleaning service and throttle body cleaning
Many vehicle repair and maintenance shops want to sell you supplemental services that cost them almost nothing. But they can charge you a lot of money for these things. Throttle body cleaning and fuel injector cleaning fall smack dab in the middle of this type of “maybe you need it, likely you don’t” basket of vehicle services. We recommend using a trusted shop, avoiding repair and maintenance chains, and only using your dealer for warranty-related or specialty repairs. If your manual specifically lists fuel injector service, but all means, do it. If your vehicle is running poorly and your trusted mechanic tells you these services are the cure, proceed with confidence. Otherwise, you should save your money.
Read more on the topic of Car Owning here.
FAQ
- Is fuel injector service really necessary?
No, fuel injector service is not usually required. Unless your vehicle is running poorly or the owner's manual specifically calls for this procedure, save your money.
- How much should a fuel injector service cost?
It should not cost anything if it isn’t needed. If it is, the cost is generally between $150 and $200 and is often bundled with other unnecessary services such as throttle body cleaning.
- What does a fuel injector service do?
Nothing usually. It is often unnecessary and almost never called for in any owner’s manual. The excuse many shops who sell this service use is it removes “carbon” from your fuel injectors. If your car is running normally, there is no indication that this service will do you any good.
- Can I clean my fuel injectors myself?
You may be able to clean your fuel injectors yourself, but why would you? If your car is running normally, there is no cleaning required. If it is running poorly, a problem with a fuel injector is a low-likelihood cause. Modern engines have high-pressure fuel systems. Proceed with caution if you must, but we suggest DIYers not touch this part of the engine.
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