There is a hesitation when starting from a dead stop. It seems to be happening about 1500 rpm and most of the time is a slight pause. some other things I noticed is it only does it when warm, if i go wot it is worse and bogs til 2500. There is no codes but i was able to get it to throw a cylinder 1 and 4 misfire by putting it in 2nd and getting hard on the gas and it will bog til 3k, only happened one and since cant get it to come back. The plugs are 500 miles old, I replaced the cylinder 1,4 coil pack with no change and tried swapping both with known working packs, no change. Idle is solid but once in a great while will stumble for a split second. Car is a sport shift AT. Any suggestions on what the cause is or anything to check?