[Cjw8733]

Does anyone know why my Kia would have a miss when turning the heater on and when taking off from a stop position it is not the coils I already checked ,AutoZone said cylinder 3 was miss firing

 

[demag]

Sounds sort of electrical doesn't it. Have you tried new plugs? Worst case scenario have you had a compression test done?

 

[noublue]

Try swapping plug positions see if misfire moves, i presume you swapped coil positions and misfire didnt move. if it is not a plug a compression test would be next or you could try disconnecting injector to see if that makes a difference.