p0171 replaced vacum lines and hoses

Question

p0171 converts to a ecm231 or 232. replaced manifold nipples and numerous hoses. replaced mass air flow meter.cleaned throttle.air pump operates and evap system looks good.drive car for 15 miles and code comes back and wont clear until car cools down.also replaced o2 sensor

Answer 1

Check the air filter first if its clean,

check for intake leaks (start the car and spary brake cleaner near the hoses and intake area and see if idle changes if it does you have an intake leak, dont spray directly on wires and hoses)

next check the fuel pressure next, also double check the hoses to see if its in the correct place. it could also be a misfire so check the spark plugs