What Causes the Engine Fault Light to Illuminate After Adding Fuel Additive?
3 Answers
After adding fuel additive, the engine fault light may illuminate due to carbon deposits being washed down, causing slight pipe blockage. Continuing to use the additive will restore normal operation. The function of fuel additive: Fuel additive, commonly known as the third-generation gasoline detergent, is designed to address carbon deposit issues in the fuel system of fuel-injected vehicles, quickly restoring the engine to optimal performance. It also compensates for certain deficiencies in gasoline and imparts new beneficial properties. Composition of fuel additive: Fuel additive primarily consists of more than ten components, including nano-molecules, cleaning activation factors, antioxidants, anti-corrosion agents, and demulsifiers. It is specifically developed to target harmful elements in fuel such as sulfur, gum substances, and engine carbon deposits, thereby enhancing power, promoting combustion, providing anti-oxidation, anti-wear, cleaning, dispersing, demulsifying, anti-corrosion, and lubrication effects.
After my last refueling, I casually added a bottle of fuel system cleaner, thinking it would clean the fuel lines. However, the engine malfunction indicator light came on right after ignition, which scared me into checking information and asking friends. It turned out that the ingredients in the cleaner were incompatible with my car. Some additives can dilute the fuel, causing the oxygen sensor to falsely report abnormal exhaust, or loosened carbon deposits might clog the fuel injector, triggering the ECU to illuminate the warning light. It's also possible that I added too much, and the excessive concentration activated a protection mechanism. If you encounter this situation, don't panic. First, turn off the engine and wait for about ten minutes; restarting might turn off the light. If it remains on, you'll need to visit a professional shop to use a diagnostic tool to check if there's a real issue. When adding cleaners during regular maintenance, make sure to choose the right type and control the amount to avoid unnecessary trouble.
I've been driving for decades and have seen quite a few cases where the fuel additive light comes on. Most of the time, it's due to poor-quality cleaners or improper usage—like inferior products leaving residue that clogs fuel lines or sensors, tricking the engine control unit into thinking there's a fault. Another common issue is older cars with worn fuel line seals, where additive leaks can trigger warnings. When this happens, first check if you've overdone it—half a small bottle is usually enough, no need to go overboard. If the car shakes or fuel consumption spikes after the light comes on, it might be dislodged carbon deposits causing new issues. Best to turn off the engine for half an hour and try again; if the problem persists, head straight to a repair shop to check the fault codes—don't delay and risk safety. For regular refueling, I stick to reputable fuel additives and steer clear of cheap knockoffs.
