1997 Buick Park Avenue Ultra 3.8L SC with DTC P0171

Question

HI

I replaced MAP, MAF, EGR, Supercharger bypass solenoid, coolant temp sensor, fuel Injectors, Ignition coil. Still the same, recently replaced intake manifold and supercharger gaskets, Fuel filter.

I have Buick Park Avenue Ultra 3.8L superchanrger. I got two times suggestions one for any vaccum leaks and the other for any other area leaks or cracks. Recently I cleared the code and drive for about 45 minutes to one hour, after worm up engine started hestating and looks like it will stall and no power. So I stoped and shut the engine off waited for one minute started the engine "CEL" came on within 20 seconds, but car was running fine no hesitation, no loss of power I drove like that again for one hour. What could be the P0171 means at thins time.

Answer 1

P0171 Fuel system lean

Map sensor is good,MAF is good,Bypass is good Temperature sensor is good so injector are good ignition good, This cant be a  engine mechanical condition,the stalling will always be there,This is intermittent,what get me is the hesitation and no power,then you shut off and everythings fineThere is  a common failure with this vehicle it s the fuel pump relay,There is a TSB on it,No. 71-65-53. It applies to most GM. Replace the fuel pump relay, The only concept left is a fuel problem,

Answer 2

P0171 Buick Code - Fuel Trim System Lean Bank 1
Read more: https://www.autocodes.com/p0171_buick.html