When in low RPM's cruising my car hiccups and hesitates hard, like it's bucking. When I put it in nuetral and rev it I can hear and fell it hesitate. I put it on the diagnostic the other day and it didnt say it was missfiring. Everything in me tells me that its missing but it would of said so on the diagnostic. All my wires to my ignition is connected. The only other things I can think of is to change the plugs and check the wires and coil packs. Both fuel pumps are working fine also. Any ideas?