my speedo is actin up....like ill be cruzin at speed limit and my speedo will act like a tach and jump everytime i press the gas....liek it will go from 80 to 20 back to 90 then just go to any # it wants to? is the VSS(vehicle speed sensor going bad or what)....and my check engin lite is on too will that cause it to come on if my VSS is bvad or loose or shorted out....all the fuses are good tho and iuno what else to check....checked all relays under hood and dash all fuses and wires and connections