Hesitation and intermittent misfire... 2006 Lincoln Town Car

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My 06 Lincoln TC sometimes has a intermiitent hesitaion at low RPM's when begining to accelerate after slowing down for a red light. It feels like there's a misfire then all of a sudden the motor gets momentum and kicks in. This seems to occur only once in a while. I'm getting poor gas mileage(12 mpg)as well. I've changed the spark plugs and filters and no codes come up when scanned. Thinking that possibly may have a coil that is starting to go bad or a mass air flow sensor problem. Any input would be appreciated!!! Can reach John at DPCLOSER1@GMAIL.COM