Will the EGR Valve make your car Speedometer increase?

Hello,

The EGR valve will not have any impact on the speedometer of the vehicle. The purpose of the EGR is to recirculate the exhaust gases.

Now for the speedometer being off it could be due to incorrect tires being installed. If the tires are smaller in diameter that the recommended size it will show higher speed on the speedometer than actual speed.
It could also be due to a faulty vehicle speed sensor. Faulty calibration of the sensor can cause it to have incorrect output to the gauge.

Have you had the tires replaced recently? Or any other services performed?

Please let me know little more details.
Thank you.