I noticed that the car slightly jerks or hesitates at around 2k rpm ~ 37 MPH
It doesn't do it all the time. It was happening somewhat frequently and right now am not noticing it anymore. (which sucks, because I cannot replicate it to let the mechanic see what I am talking about.)

When it happens, it's a bit challenging to keep the car at the same speed (again, between 35-40 mph). And I can actually see the tachometer gauge moving up and down.

I also noticed one time driving back from Atlanta, that doing hig speed on the interstate the car also feels like it's accelerating....it's not...accelerating...and not.
During the summer I also noticed that sometimes it was hard to accelerate gently when coming out of a stop light. I had to press the pedal more and the car will of course come out fast.

All this stuff happens with the AC on or off.
Any suggestions????
Thanks!

 

look at the accelerator pedal assembly, have some seen recent comments on this part going bad
ACURA TSX ACCELERATOR PEDAL SENSOR ASSY 37971-RBB-003 @ AcuraOEMparts.com - Acura Parts from Delray Acura

 

My pedal went bad about 2 years ago and it wasn't a cheap fix either. Actually, it's really stupid design. Just a little plastic hinge which can't last forever.

 

This is what I needed to replace....

Amazon.com: Standard Motor Products APS147 Accelerator Pedal Sensor: Automotive