Sensor Range Question?

hey guys!! just went out and played with my GTP and my Digimoto. And let me say, That GTP scared the crap out of me!! I set up digimoto to the "dyno" setting to measue HP and torque, and even on a straight road with no bumps, I didnt have the guts to completly floor it. I got it to about 80mph in what seemed about 5 seconds. My tie rod ends are in need of replacement and it just snowed here a little, so I backed off. Dont want to kill myself (or worse) smash up the GTP. I got the software to read just over 200HP and I think torque was about the same before I slowed down.

But I do have a question. My car seems to have a slight rough idle in park. It has had it ever since I bought it. In drive with your foot on the brake it goes completly away. Plugs (acdelco 41-101), wires (acdelco), PCV (acdelco), Air(acdelco), and fuel filters(acdelco 'can we see a theme here?') were all changed last summer. I have heard different things about the 41-101 plug. Mainly it being too generic for specific cars. (maybe i should switch to bosch? :grinyes: )

I actually think my bad idle in park is the result of a flaky O2 sensor. When i was sitting in park, I was watching my O2 sensor voltage. It was fluctuating is it should (I think), but the lowest value I observed was .04V and the highest value was .8V. Shouldnt O2 sensors have a range of .1V (lowest) and .9V (highest)? I will try to Get a video of my screen as Im running the software. I would really like your guys' input.

But anyways, below I have included a screenshot of my digimoto software with my car idling in the driveway in park. Was just wondering if any of you educated guys could point out any possible problems. I know it says my LTFT is -2.3%, but i'm fairly cartain it isnt overfueling. As I drive LTFT fluctuates anywhere from +2.5% to -2.5%.

Also was wondering if the value for "Ignition Timing Advance for #1 Cylinder" could in some way be used to determing KR. Any ideas?



http://img181.imageshack.us/img181/3069/sensorsix1.jpg

I'm not familiar with the software being used but on your 02 sensor question it depends. Correct 02 sensor range is .1 (lean) to 1.0 (rich) volts but it depends on the conditions and how long you get the reading if it is actually abnormal or out of range. The PCM evaluates the voltage samples to make a determination and the duration. 10-15 seconds rings a bell and it depends on whether the PCM module is in closed or open loop mode, etc. Also, make sure the engine is fully warmed up. Technically if your 02 sensor was really out of range or providing a slow response or any period of inactivity a respective DTC should set.

On the ignition timing advance cylinder #1 question maybe seeing that figure go off (retard) could possibly indicate you are getting knock retard but I don't think that would be an accurate representation of actual KR from either of the two knock sensors and processing via the knock sensor module in the PCM module.

Ok, thanks Bob. I'm gonna work on getting a video of my screen because I watched real time graph of the o2 sensors switching, and the one before the cat seemed whack (at least it seemed whack based on my knowledge).