I have a 2007 Accord (4 cyc). it runs fine on local, however, when I drive it on highway, especially over 65m/h, I can hear noise when I push the gas pedal, once I release the pedal, noise is gone.

I recently did fuel system cleaning in firestone and am not sure if that was related.

 

You'll need to be specific; whine, screech, roar, growl, grinding, etc.

Also can you say if it's from engine, transmission, tires, front/rear wheels, other?

Lot's of possibilities.