What signs indicate my fuel injectors need replacing?

Several symptoms can point to failing fuel injectors, including poor engine performance (hesitation, stalling, rough idling), decreased fuel economy, a noticeable fuel smell, and a failed emissions test. You might also experience difficulty starting the engine or notice a persistent check engine light illuminated on your dashboard.

Fuel injectors are responsible for delivering the correct amount of fuel into the engine’s cylinders at precisely the right time. When they malfunction, this precise fuel delivery is disrupted, leading to a range of problems. A clogged injector can restrict fuel flow, causing a lean condition and resulting in hesitation, stalling, or poor acceleration. Conversely, a leaking injector can flood the engine with fuel, creating a rich condition that leads to rough idling, poor fuel economy, and a strong fuel smell. The check engine light is often triggered by issues with fuel injectors because the engine control unit (ECU) monitors the air-fuel ratio and other parameters related to fuel delivery. When the ECU detects an imbalance or a malfunction, it will illuminate the light and store diagnostic trouble codes (DTCs) related to the fuel injector problem. While a check engine light can indicate numerous issues, if it’s accompanied by any of the performance issues mentioned above, it’s wise to investigate your fuel injectors. Diagnostic codes, such as those indicating a misfire or lean/rich conditions, can help pinpoint the problematic injector(s).