P0171 too lean bank 1

[Jerry99]

Hello I am trying to find out if I have a bad o2 sensor
any help on this would be great
1999 Z24 Conv 2.4 aem short air induction

[thisnametooktolong]

Probably not with a 171.

You can check it out with a scanner. The lean condition is usually caused by a few things. Low fuel pressure, plugged up injector, Intake leak? A good hole in just the right place in the exhaust., and a bad Hego. That thing is an OBD II so you can graph the Hego. If it is switching but not going above (around .5 or .6 volts) it could be a quad driver or the wires/ plug and of course the hego itself. This one takes a mind to actually make a diagnosis. Without the hands on I refuse to guess

Sorry this is not a sit at the computer and just guess kind of thing

[JerryZ24]

It was the fuel pump
and boy was it pricey