Engine light comes on so they scan it and they told me egr valvue

The problem is that your EGR valve needs replaced. What these do is they allow a precise quantity of exhaust back into the intake manifold; Provides a great help for an efficient combustion process and improved engine performance, when thes go bad your perfomance drops off and it does not run as clean.
The EGR valve, or Exhaust Gas Recirculation valve, is a vacuum-controlled valve which allows exhaust back into the intake manifold in controlled amounts. The EGR valve can clog and get contaminated over time by carbon buildup, at which point it will require replacement. A malfunctioning valve can cause the engine exhaust pressure to drop and send engine warnings to the computer. It can also cause engine back pressure to drop, reducing gas mileage and engine
This is for a dodge ram, as I have no idea what car you have but this is a general tip.

Unclip the exhaust tube from the side of the valve. You can do this by hand. Shift the tube from side to side until it slides off.Use a flat-head screwdriver to remove the EGR valve from the exhaust tube. There is a screw on each side of the tube.

Disconnect the harness from the EGR valve. Use your hand to pull up on the tab and slide the harness from the valve.

Use a flat-head screwdriver to remove the two screws that secure the EGR valve to the cylinder head. Remove the EGR valve and clean the surface of the cylinder.

Attach the new EGR valve to the cylinder head and tighten it down with the same screws that were previously installed.

Reattach the harness and reattach the exhaust tube to the valve. Tighten the two flat-head screws that hold the tube to the valve.

Reattach the hose to the valve and use your hand to attach the clip to the hose.