1997 Buick Park Avenue Ultra 3.8L SC with code P0171, any suggestions?

Question

Hi

I checked fuel pressure at startup is 50 psi, then at engine idle drops down to 30 psi which sounds like low.

Then at idle disconnected vacuum hose from fuel pressure regulator no change at pressure ( remains at 30 psi)

DTC P0171 don't go away

Any suggestions

Thanks in advance

Answer 1

P0171 code is for the Fuel Trim System Lean Bank 1 which means that there is either not enough fuel or too much air going to the engine. If the fuel pressure is OK, I suggest checking for intake air leaks. If no leaks are found you may have to replaced the O2 sensor.

P0171 BUICK - Fuel Trim System Lean Bank 1

Read more: https://www.autocodes.com/p0171_buick.html