Hic-Up?

I've recently been getting a...sorry for the un-technical description..."hic-up" when I change gears and step on the throttle. At first I thought I might have it in a low gear for the speed I'm in. When I press on the throttle the car sort of stalls. When I ease up on the gas it's fine. That car has not stalled while driving or otherwise. In my little mind I'm thinking...clutch? fuel pump? bad gas? Otherwise the car runs and idles great.

Any thoughts? 2006 Mustang GT 5.0.

Sorry for my ignorance....when you say "throttle pedal" you mean the gas pedal. The sensor is the TPS or throttle position sensor? That looks like something I can do myself.....? Thanks, btw, for the reply.