P1457 is for a leak in the EVAP canister system
That seems completely unrelated to speedometer or VSS.

Look for loose connections at the back of the cluster. If the VSS itself were bad it should set off another code (P0500 for manual trans, P1791 for auto). Since you don't have those, the ECU must be happy with the signal its getting from the VSS.

After ruling out bad wiring, it might be a bad gauge in the cluster.