I Got a Reading of po 300 & p1404 do i need a new EgR or how can i check it myself.

Welcome to AF!!

I moved your post here due to the fact that the trouble code thread is for posting of trouble codes only not questions about car problems. Your car is experiencing random misfires. You don't say what size engine you have but start with plugs and wires or connectors then coils it the plugs and wires don't correct the misfires.

As for the EGR code simply remove and clean it and make certain the passageways to the engine are clean before you do anything else. Correct the misfires first as that can contribute to the egr issue since it does not work properly. If after cleaning the egr and passageways if the problem does not correct itself then it may need replaced.