issue with Check engine light

[chrissbee77]

I have a 01 grand prix gt 3.8 non/supercharged. I had a new cat put on about 3 months ago and. i just changed the front oxygen sensor. I keep getting a check engine light that says (bank 1 sensor 1 below threshold). I borrowed my friends scanner here is the list of readings( i dont know what they mean sorry)
MIL ---- -on
ABSLT TPS %-----0
engine spd ---- 832
carc load ---2.7
maf lb/m ---2.7
map "hg" -11.2
coolant f -162
iat f---------75
ign adv(peg) - -22.0
st ftrm1 % --- (3.1-2.3) this kept going in between so...
lt ftrm 1 ------4.7
veh spd---------0
fuel sys 1 -------clsd
fuel sys2---------n/a
o2s11(v)----------.765
st ftrm II ----------1.6
o2s12--------------.050
mil dist---------------88


I just want to know what i need to change in order to fix the car. thanks guys.

[troy1]

What brand of CAT did you replace your bad one with?

[driver540]

Dont know what hg your map sensor should be at where you are from, but in Ohio its suppose to around 29. If thats what its suppose to be there then I would look into the map sensor.

[chrissbee77]

the cat came from the dealer almost 640 with labor and all. I live in missouri are you saying that my MAP sensor is bad

[driver540]

Im not saying that. Your hg depends on altitude/above below sea level. Its different in different areas. I was sayin to ask or look into what its suppose to be. Like I said, in Ohio the norm is around 29.

[chrissbee77]

how do i find out what it's supposed to be at?

[tblake]

I would check the wiring to the O2 sensor.

Does the O2 voltage fluctuate back and forth or does it remain steady?

[CrazyHorst]

Couple of things.

As far as the "front O2 sensor" I assume you are talking about the one in the rear 2-4-6 manifold (?)

Some vehicle lines (and I forget which ones these days) using L36 and L67 had 3pc O2 sensors, one in the RH 2-4-6 manifold, one pre-cat and one post-cat. So this makes nomenclature more difficult.

TBlake is trying to tell you that you should watch the O2 sensor voltage (bar graph or whatever) in real-time as the engine runs (idle is fine after it warms up and is in "closed loop" fuel control...about 5 minutes after startup or so if you just idle). It should toggle somewhere in the range of 0-1000 mV in a slow moving sine wave function were it plotted out over time. A single snapshot of O2 voltage means nothing.

[tblake]

Originally Posted by CrazyHorst

....TBlake is trying to tell you that you should watch the O2 sensor voltage (bar graph or whatever) in real-time as the engine runs (idle is fine after it warms up and is in "closed loop" fuel control...about 5 minutes after startup or so if you just idle). It should toggle somewhere in the range of 0-1000 mV in a slow moving sine wave function were it plotted out over time. A single snapshot of O2 voltage means nothing.

What he said.

[chrissbee77]

it seem to fluctuate between 10-865 pretty consistently. after it is idle for about 5 min. i checked the voltage to the oxygen sensor and the wires and they seem fine. any ideas