i've got a 2000 ford ranger 2.5 5 speed ,that had three codes come up a po401,po402,p1401.took it into a mechanic and he tells me its the fuel pump,because it wasn't keeping 40lbs pressure,changed dpfe,inspected vehicle for faulty wiring @ engine harness and still, the engine light will not go out......i myself do not know too much on these new engines,but what i found out on the internet is that a code p171 or 174 means fuel pump,now i don't know if the fuel pump needed to be changed "cuase the check engine soon light is still on or what? does anybody here ever have this problem and could share the recommendation to cure this situation? please help