What are typical signs that a leaking fuel injector is present in a vehicle?

A leaking fuel injector often leads to excessive fuel consumption because the injector is designed to deliver a precise amount of fuel into the engine’s combustion chamber. When it leaks, it allows fuel to escape into the intake manifold or the combustion chamber without being used efficiently, resulting in a richer fuel mixture and thereby causing the engine to consume more fuel than normal. This excess fuel not only affects fuel economy but can also lead to other issues such as rough idling, increased emissions, and potential engine misfires.

The other choices do not align with the typical symptoms of a leaking fuel injector. Decreased engine temperature is not directly linked to fuel injector leaks, as the issue primarily impacts combustion efficiency. Increased power output typically signifies optimal fuel delivery and combustion, not a problem with leakage, while negligible changes in performance would suggest that the injector is functioning properly to some extent, which contradicts the characteristic of a leaking injector. Thus, excessive fuel consumption is a definitive indicator of this issue.