Dawoodster

I got a code P0300 misfire across all cylinders, so I changed all of the plugs and coil packs. I then got a code P0135 Bank one sensor 1 so I replaced that with a sensor from Advance Auto, and the same code came back again today and my car is not accelerating like it is suppose to, like it has no power then eventually it kicks in and goes. Can someone tell me where to go next, all help will be greatly appreciated.