1998 ford taurus got po5000po171po174p1502what do i have to do thanks jim

Question

having trouble driving car stays in 1st gear for a little while and when the OD lite starts flashing then car will start shifting having four codes come up po500,po171,po174,p1502
dont know where to start. po174 use to come on and off by self but now it is on for good
please help

Answer 1

P0171 Fuel trim lean Bank 1

P0174 Fuel trim lean Bank 2

P0500 Vehicle speed sensor (VSS)

P1502 VSS intermittent

Without the VSS the transmission will not shift right and the OD light will flash because it has detected the fault, As for the lean condition check for vacuum leak especially at the PCV hose which tends to rupture