P0171 BUICK - Ultra

Question

Hi Reynaldo,

I replaced fuel Injector on bank1.
After about 2 or 3 minutes CEL light came on again, I cleared code again but after about 1 or 2 minutes light cam back on. Any suggestions?

Thanks in advance

Answer 1

When you clear a code and it comes right back on, this is considered a hard set code. For P0171 to reappear its truly a lean bank 1 (Bank 1 is where cylinder 1 is at). The causes of this are Damage vacuum hoses,this includes the PCV valve. Low fuel pressure, pressure spec are 48-55 psi at idle. Low fuel pressure the PCM can compensate for but will set code P0171. Exhaust leaks causing 02 sensor to appear lean. Here is a vacuum diagram use brake cleaner or carburator cleaner especially at the intake and listen for any RPM changes,And dont over spray any component,just enough to check for vacuum leaks