What is a common sign of failing fuel injectors?

A common sign of failing fuel injectors is rough engine idle or misfires. When fuel injectors begin to fail, they may not deliver the correct amount of fuel to the engine. This can lead to an improper air-fuel mixture, causing the engine to run unevenly. Symptoms such as rough idling, hesitation during acceleration, or misfire codes may be noticeable.

A well-functioning fuel injector should atomize the fuel properly, ensuring efficient combustion. When they fail, the result can be poor fuel delivery, which affects engine performance and may lead to inefficient running conditions indicated by the observed symptoms. Poor performance such as misfires not only reduces power but can also lead to increased emissions and potential engine damage if not addressed promptly.

The other options do not align with the symptoms observed in failing fuel injectors, as an increase in fuel pressure is typically associated with a different set of issues, while improved acceleration and no changes in engine performance would not indicate injector failure.