P1505, P0171, P0174 on 1997 Mazda b4000. replaced PCV, Tried new IAC, runs ok sometimes, except under load

Question

P1505, P0171, P0174 on 1997 Mazda b4000. replaced PCV, Tried new IAC, runs ok sometimes, except when u try to put it under load, other times cant keep it running at all.

Answer 1

HI there,

the P0171 and 174 codes are for a lean fuel mixture. Many times when it's on both banks like this it's an issue with the mass air flow sensor or the fuel pump. Since sometimes it's running better, my money is on the maf sensor. The idle code could be a result of the engine running poorly, so I would take care of the lean mix and then take it from there.