GM-GMC: sputtering, air flow sensor, airflow sensor

Question
Just yesterday my truck started sputtering but only during specific times of opperation.
-At a standsill idle if feels like the engine wants to die.
-When acceleration from a standstill idle it sputters to get up to speed.
-And when going up a hill it starts to sputter.

I spoke to my dad and asked if he thought that it was a spark plug problem and he suggested that it might be an air flow sensor problem. He directed me to this website before going to a repair shop.
  My truck is a GMC Sierra 1500, year 2001 with only 49600 miles on it and it has had its 30k mile service.
  Thank you for your assistance.

Answer
Rachel,  

  The problem your truck is having can be caused by many things. The first thing I check is to verify that the Fuel filter on you truck has been replaced, a Low fuel pressure at idle, initial throttle and hard throttle could be caused by a plugged fuel filter. This is a cheap, maintenance orientated fix that should have been done on your truck already anyways. If you are taking your truck to a dealership they often neglect this filter with their "Tune-ups". The airflow sensor could also be at fault, basicly it measures the airflow into the engine by the temperature drop it creates over two heated elements. The amps it takes to keep the heated elements is the calculated to tell the computor the amount and desity of air entering the engine. I actually just had one of these last week and the customer had his truck towed just because the two heated elements had oil on them from a K&N filter. This may be something you want a tech. to do since they are very fragile and expensive! I usually hose them of with a good quality intake cleaner and then dry them immedeatly with compressed air. Its important not to touch the elements and don't use Varsol or other parts cleaners, intake or carb clean is much better. also when blowing off don't use full line pressure of the air hose just enough to dry them. Hope this helps.