anyone know anything about tunes , i need some help on o2 sensors , when i had my motor tuned they turned them off , now i got a hp tuner, i want to turn them back on , i went through the dct's and turned them back on there ,but i am still getting no activity on both
i check the voltage i got 13 at the plug , i check the sensor at a idle i had .8 coming back,

thanks

 

Depends on the car. Older cars has O2 sensors only before the cats, newer cars use O2 sensors , both before and after the cats. The rear cats are used to monitor the performance of the cats and on late model cars can also cause minor adjustments to the fuel mixture. The ones before the cats (upstream sensors) are the main controllers of the fuel mixture and if deactivated the engine won't run properly. The rear cats can be deactivated, but the only reason for doing that is to avoid getting the check engine lamp lit if the cats were removed. The 13 Voolt you are seeing is probably the power going to the heaster in the O2 sensor. The sensor also has another circuit which sends a varying voltage to the PCM/ECM (0.1 to 0.9 Volt) according the amount of free oxygen in the exhaust. This voltage tells the PCM if the fuel mix is rich or lean.

 

right now i have installed new sensors , and yes i have 13v at the sensors and i have .8 coming from the sensors , the issue i am having is i went in my hp tuners and enable them but i need to set the parameter within the tune , after it warms up i see no activity on both , by me just enable the codes that wont turn closed loop on ?
i need to learn how to set the parameters within the tuner
thanks

 

i have check everything i know , i dont know were to go from here
her is a pic of my wiring , please let me know if its not right

 

After reading your posts, I have several questions.
1) What engine and year are working with?
2) What modifications were done?
3) Who did the tuning?
4) Whose lame idea was to turn off the O2 sensors?
5) What is the sketch you posted supposed to represent?
I used to be able to read minds, but I have lost that ability. lol
As for the O2 sensor operation, the change in output voltage is the result of the PCM changing the fuel mixture. If the PCM does not control the injector duty cycle, the fuel mixture does not change and the output voltage of the O2 sensors remains the same. The output voltage you are seeing from the O2 sensors (0.9) volt is the result of an extremely rich mixture, which is not being addressed by the PCM, or the settings of the PCM have been molested to the point that it is not able to correct things. Check the short term and long term fuel trim and see if the PCM is attempting to correct things.
Also check fuel pressure, and verify that the injectors are being pulsed and not stuck ON due to a short to ground on the control lead.
http://www.obdii.com/articles/Unders...n_Sensors.html

 

sorry , i am just about to loose it here ,,
motor is a 06 silverado
PCM is a 01 camero
a local guy did my tune he has a great name for doing tunes at thr time of dyno there was something wrong so he turned them off so i would get a engine light , i have replaced both o2 sensors and have had my o2 turned on and now i get a engine light the drawing is of the plug showing the wires, i was thinking maybe it might have been miss wired , i do have a log and my tune if you would like to look at it ,, like i said i just dont know what wrong , i have checked the wires the ohms out fine , the car runs great other than gas mileage , ( .9 ) now i know why ,, anything you can do would be great ,, i dont know were to look

thanks

 

tune and log

 

How are you measuring the voltage from the sensors? Are you using a DVM or the readings from a scanner. The scanner shows what the PCM is reading, if the PCM sees the same voltage as the DVM, then it should be attempting to pull the fuel back. If it does not see the sensors, then there may be a wiring error, especially since parts of different cars and year were mixed. A wiring diagram for the PCM would be a help in making sure thing got wired properly. Have you tried scanning the PCM and see if it is complaining?

 

i have looked at wring diagrams for a week now and traced wires , i was using a volt meter to check voltage , i do use the scan feature thats were my log comes in , you can see it dont really change from 443-451 like i said i dont know were to go from here , thats why i posted that pic of my sensors to see if anyone can let me know if they are right colors wise if so i can move one to something else
thanks

 

it says 01 camero the plugs are red and blue ,, does someone have a wiring diagram? i have look and several , maybe i am looking at the wrong ones,,, also my o2 plugs has 4 wires black,,pink ,, tan ,, purple , does that mean they are isolated ground ??