What could be causing the 3rd and 6th cylinders to misfire? on 2004 Ford Taurus

My 2004 Ford Taurus seems to start ok, but does not run right. When you press on the gas the car seems to be starving for fuel and pauses for a moment before going again. The RPMS drop and then go back up suddenly the harder you press on the gas pedal.

1 answer 2 comments
Common problem is vacuum hoses! Also depends on which motor you have. Need to know exactly which! Pushrod or DOHC.
I have the DOHC....thanks for the reply
Idle ok, smooth or rough? There is a vacuum circuit i think that pulls vac. from those two rear cylinders, have it checked IF rough idle and surge is present also. (Possible!)