98 Honda Civic speedometer?

So my speed gauge is jumping all over the place I change speed sensor and still jumps everywhere when I drive. Does anyone know what's the problem

Sure, If you replaced the VSS and the wiring is good. The speedometer itself is bad.

It probably is the speedometer that's faulty sometimes the soldering connections are bad or the gauge itself fails.Besides that you need to trace the wiring be sure it's not frayed or damaged and that the ground is good. On some vehicles the dash/cluster assembly can be removed and then the gauge can be replaced pretty easily in other cases it might be easier just to go to an auto wreckers pull the whole cluster/gauge out of a car like yours and install it into your car.Youtube etc might have do it yourself videos showing you how to replace the assembly.

Hope that helps and best of luck.By the way if you do install a different mileage indicator you'll need to record what the old mileage was and what the mileage is on the replacement part and let your Ministry Of Transportation know that what the replacement mileage indicator says the mileage is and what the old part stated as the true mileage on that vehicle.Note it's the Law.