02 sensor questions

Greetings-

Twice now and shortly after refueling on road trips, I get a CEL. When putting the reader on it, I get a "PO157 02 Sensor circuit low voltage bank 2 sensor 2".

Is this as straight forward as replacing the 02 sensor? (I would replace them both if one is truly out).

I ask because I vaguely remember that other things could cause this code?

Thanks for any input here.

hows your fuel mileage,.

last 2 trips I averaged 22mpg mostly highway miles.

Change the O2's

Will do. I will report back on results.

Okay. Replaced all 4 02 sensors. They were factory originals with 160k on them. 2 long trips after replacement, I have not thrown the code.

Differance in gas mileage? Negligible....was getting 22mpg avg (highway) and after 02 replacements has gone up to 23mpg avg. I suppose that's not bad considering in 96 they were originally rated at 25mpg highway.

Also, for those of you that plan on replacing your sensors, two pieces of advice; invest in the special thread chaser to clean up the threads after removal of the old ones and jack up the front end and do it all from underneath. Access is much better that way.

Wagoninabox wrote:

2 long trips after replacement, I have not thrown the code.

Differance in gas mileage?  Negligible

makes sense. The rear O2s don't affect AFR.