I have been playing with a scanner all night and have seen so many numbers my mind is boggled but i am trying to find why my motor idles very poorly and rich. One thing i do remember was my left o2 sensor at idle would spike at over 1000. At wot it seemed to be in the mid 900's for both sides. This seems kinda high to me. What could it mean?

 

my left side o2 flucatuates from 100 somthing up to about 850 and my right side stays put at 443mv

I think your right one shouldnt move at all if any.. and it should be near 450mv all the time... the left should be about 100-850mv, This is what I was told..

 

whoa now. Your PRE cat o2's should always be fluctuating from 100-800ish mV's. If you have an obdII car then the AFTER cat o2's should be staying around 450 mV. If one of your o2's is always at 450 mV it may be dead.

 

MY O2 went upwards around 900 and it still is in spec. Check your IAC position and take it out and clean it with some carb cleaner. Thats what I didnt when my car was running alittle rich and that fixed the problem. The IAC mounted right under the TPS, make sure to disconnect the wires from it and never crank the engine if the IAC is outside the TB and hooked up to power. I noticed first hand that it's like a small rocket ship. give that a shot and see how it goes. Are you picking up any other unusual numbers on the scanner?

 

i dont understand how it can spike over 1000 when the mV range the sensor functions in is 0-999mV.. 1000 isnt really possible.

both sensors left and right should start cold at 450mV and as they warm up they will slowely begin to fluctuate between 0-900mV until they go so fast you cant effectively read them on the scanner.. if one of them isnt then it is not working properly or theres a wiring issue somewhere.

 

Hyperspeed:

You really need to get your stories straight.... in the other post that a few of us spent a lot of time trying to help you with, you insisted it was the passenger side pre-cat (B2s1) that was varying from 100-850mV, and it was the passenger side after-cat (B2s2) that was stuck at 443mV. You told us that no matter what you did, the Snap On scanner you used would not show you anything but Bank 2 (passenger side). Now you are posting its the left and right sensors that gave you those readings. And I don't recall anyone telling you the left should jump around and the "right one shouldn't move at all... and it should be near 450mV all the time".

 

Sorry Fred, I do mean the right side... I keep thinkin that B2s2 is the right side and B2s1 is the left.... MY BAD... I havent got the chance to get on the scanner again and get into the left side..... Sorry Man, I do appericate your help ALOT !!!

Theres only a few of you guys on here that always lend me the helping hand, yourself, shoebox... I am thankful for your guys help. Just try to deal with me as I'm learning new stuff with the lt1 everyday

 

O2 sensors are suppose to jump around at idle. The only time they provide usable data is at WOT. And that is to put it simply greater than 900 rich, less than 900 lean.