okay guys i have a 97 camaro ss lt1... i have a check engine light p0131... the first bank first o2 sensor is reading low voltage... so hears the problem i have lt headers and i checked the driver side o2 in the collector all wiring is fine and sensor was replaced about 2000 miles ago... im also getting 2 other codes for the rear o2 sensors not having activity(ory so there are no sensors i havent had them tuned out yet) and the car is misfiring on cylinder 7(code p0307) checked wires all look fine also replaced 2000 miles ago... okay here is my question if i put my scan tool in operational data mode it tells me that the bank 1 first o2 sensors is reading 0.010v and that the bank 2 sensor 1 is reading 0.755v and both rear o2s read 0.455 because they are not connected im assuming... now should the bank 1 sensor read simialar to the bank 2 sensor? and would this cause it to misfire? mods are k&n cai, pacesetter lt,ory,walbro 255 fuel pump,and hypertech airfoil. any input would be really helpful im lost thanks in advance

 

I too have a similar problem..

Would having a bum O2 sensor really make that much of a power loss?

 

After about 3.5 minutes from startup, with the coolant over 120*F, the O2 sensors should be heated up, allowing the PCM to enter "closed loop". When that happens, both pre-cat O2 sensors should swing back and forth rapidly, over the range of 0xx-9xxmV's. They cycle about 9 times per second, so you need a data logging scanner with a scan rate of at least 10 frames per second to even read them. The left and right sensors will not have the same voltage reading. Each bank of the engine is controlled indpendantly.

If the O2 sensors exhibit a steady reading, there is something preventing the PCM from going into closed loop. Are the actually "steady", or did you just pick a couple points off a data log?

The ~450mV reading for the after-cat sensors is normal, because when you unplug the sensors, the PCM reads its own "bias" voltage, which is 450mV.