05 TL 97000 miles, cel came on at idle, reset and then it came back on again while idling after 10 or so drive cycles.
Question is what should my long and short term fuel trim readings be ? Im leaning toward a faulty 02 but i know just enough about driveability to get me in trouble some times.

 

I would think long term 1 to 2%.
Wouldn't think an O2 sensor as that has passed the test before the P0174 code. Check any vacuum leaks and intake boot, but normally both P0171/P0174 codes are set if dirty MAF sensor or if in the intake system as both banks are affected.