so i put my car in the shop, replaced opti, coil, plugs wires thinking that would resolve the issues with my rough idle. car is still idling rough but now, sometimes when you first start it there are 3 or 4 quick knocks before it fully fires. anyone know what this could be? its a bit difficult to describe but between the time when the engine starts to turn over and its fully running, the knocks occur. i'm also getting the check engine light that starts to flash when acceleration occurs. anyone run into this?