Engine Performance problem
2007 Chevy Truck V8 Two Wheel Drive Automatic 64000 miles

I have a 2007 chevy silverado with check engine light on. Code states it is the throttle/pedal position sensor p0121. Is there a TPS sensor on the throttle body on this model? Or is it just the pedal sensor? when I called the parts department they are telling me that It is the whole gas pedal assembly? I disconnected the sensor on the pedal and sprayed air in it and unplugged battery overnight. Truck ran fine for about 10 miles then the check engine light came back on. I drive in real dusty dirty job sites all day, inside of truck is very dusty. The truck has not been driving bad, every once in a while you can fell a little miss when you hit the gas. Would the gas pedal be hard to exchange, looks like 2 bolts and the plug???? thanks, Ann