2001 gmc jimmy po171 lean bank code what could be the fix is it a possable o2 sensor

The code is for the O2 sensor in bank one. The sensor is telling the computer the fuel mixture is too lean so the computer causes the injectors to have longer "on" time to richen the mixture.
The sensor could be faulty, or something in the engine such as a vac leak or other problem.

P0171 System too lean bank 1
P0174 System too lean bank 2

Last time you changed your fuel filter?
Look for any vacuum leaks.

Did you replace the fuel filter as well?

if i remember correctly that code is running lean on bank one (drivers side) of engine. normally the cause of this code is that the left side o2 sensor in front of the cat. converter is not reading correctly. to fix the problem i would first stop at a parts sore where they do free system scans to erify that is is that particular sensor. if that is the case then the solution is to replace it with a new one. hope this is of help, thanks

po171 fuel injection system to lean bank 1 po174 same thing but bank 2 that could be the oxygen sensors

system too lean in bank 1. clean your mass airflow sensor, replace fuel filter. iff all else fails check you fuel pump.

most likely this is the O2 sensor for that cylinder bank is defective.

P0171 - Fuel Trim System Lean Bank 1
YOU WILL NEED TO AVE THE DEALER TEST THE O2 SENSOR FOR PROPER SWITCHING, RIGHT NOW IT SHOWS ALWAYS LEAN, THIS MAY BE THE SENSOR OR THE ENGINE MAY REALLY BE LEAN ON FUEL AIR RATIO, AS FAR AS THE SMOKE GOES THE 2 ARE PROBABLY NOT RELATED, HOW MANY MILES ON CAR? IF THE MILES ARE HIGH THEN REPLACE THE O2 SENSOR ON THE CYLINDER BANK WHERE # 1 CYLINDER IS LOCATED, THE SENSOR IS THE ONE BEFORE THE CATALYTIC CONVERTER.

Basically this means that an oxygen sensor in bank 1 detected a lean condition (too much oxygen in the exhaust).

Po171 is a lean condition on bank one ( only one) o2 sensor in front of the catalytic converter. Could be a mass air also could be a vacuum leak. or a bad o2 so dont jump to expersive parts unless you have another car to swap stuff around