Can Someone Please Help Me Diagnose the problem I'm having with my 2011 Chevy Impala

Does is get smoother as speed increases and you ease off the gas pedal? How well does the car coast if you pop it in neutral?

Have never put it in neutral. And, yes it does ease off as my speed increases.

Chevy Impala 2011 3.5L V6 Throttle Body Failure If you watch the YouTube video I just mentioned before this sentence, that is what my car sounds like, but, it doesn't make the sound quite as often - just intermittently, and, mostly when I have been up in speeds in excess of 45 MPH for a good bit of time.

-Chevy Impala 2011 3.5L V6 Throttle Body Failure- that is the video on YouTube.

Meant to mention how now it sometimes makes the noise and feels like it wants to try and stop when I am just driving along. Those times are not as often as when I stop and press the gas pedal, though.

Also, my check-engine light does not come on, and, when the dealership ran diagnostics on I'm car, they didn't get any code to come up as being wrong with! It.

***my car***

That sounds like an ignition related misfire, I would start by changing the spark plugs and spark plug wires if they have not been changed recently as they are "consumable" items that should be replaced around every 100,000 kms. I I problem persists I would move onto replacing the ignition coil a it I will component that wears also. If still no change I would have a compression and leakdown test done before replacing t throttle body,bad/burnt valves can cause a misfire and rarely throw codes