Vibration in Gas pedal on 2001 Buick Park Avenue

When I am driving my car i can feel a vbration in the gas pedal. What could this be.

Asked by for the 2001 Buick Park Avenue
You feel a vibration in the accelerator pedal. I wonder if this could be a misfire? Is your Check Engine Light illuminated? Is the vibration only experienced as you accelerate or is it felt as you are under steady load?