I have a 95 bonneville and have code PO 131 anyone know what this code is, and what could be causing it? Thanks!!!

I searched it and got:
P0131 is Heated oxygen circuit ( Low Signal Voltage )

How old is your O2 sensor?

Hmmmm, for some unexplainable reason the code listings for 1994, 1995, and 1996'* are missing from our TECHINFO, but, since they are similar to other OBD systems, it is likely this:

DTC P0131 HO2S Circuit Low Voltage Sensor 1

I too didnt see it in "techinfo" Anybody know the cause of this code? Thanks in advance!!! O just replaced the o2 sensor and its still blowing this code.

Did you reset/ clear the code from the PCM?

yes I cleared the computer

This is the diagnostic information for that code. Unfortunately, most of it requires a scan tool. It'* for a 2003, but should be similar, if not identical, with the cause and diagnostics. P0131