Engine problems

sounds like fuel relay or fuel pump to me

Was told by mechanic one of the two fuel relays wasn't getting power but then said the distributer was bad. After replacing it car runs but very sluggish and spuddering and sounds like its gargling and has P0300 and P0181 codes. Any idea on what he did wrong?

Also shows this code

Random mutable misfires means it is effecting all cylinders. That would indicate to me its a fuel delivery problem weak fuel pump or clogged fuel filter or air mixture problem such as a vacuum leak in the valve cover gasket, intake manifold vacuum hose or fuel fill cap leak, EGR leak.