My Service Engine Soon light came on a couple weeks ago, for a bad sensor and a missfire in cylinder 2. I cared it to the local Ford dealer, and they replace my mass air flow sensor, and the coil pack on cylinder 2. Well this seemed to solve my problems, but the other day I gave my car a little gas got around 4K rpm and my SES light came back on (blinking), and my engine started sputtering for a few seconds. What do you guys think would cause this, I contacted Ford today and they said the coil pack they installed my be bad.

 

well since Ford seems to have an opinion, I'd let them deal with it. I'd ask them to pull the plug from #2 along with the coil pack. If they're dealing with a misfire then the plug is almost certainly fouled. Also ask for a compression check on that cylinder. Those are all super quick diagnostics that should be done when you start getting a misfire condition that recurs.

 

blinking SES means misfire code.