This is intresting. I'm really going to look into this.

 

Well I tried the resistor trick and it did not change the A/F ratio at all. Apparently the PCM measures the resistance in the O2 Sensor circuit and uses that as a baseline before it goes into closed loop.

 

How can it measure the resistance, know that it is different, and compensate for it, all while still maintaining an a/f of 14.7:1? Especially running in open loop first.

 

I'm making an assumption based on how my car reacted. According to my calculations a .450 ohm resister should have made a significant change in reported A/F ratio. I'm using a dynojet wideband commander so I can read very small changes as small as .1 AFR. It didn't change the A/F ratio or long terms at all. I tried it on the signal and signal ground wires to no avail.

 

So, you changed the Voltage seen by the O2 sensor. I'm wondering if the computer picks up the range (0 to ?) of the current and changes it's parameters accordingly. That's crazy. I'm glad you attempted to do it though.

 

Yes, he changed the voltage, which is the output that the sensor gives to the PCM that is interpreted as a lean/rich condition.

 

i never used the above mentioned program. but when you tune as much as some of us guys do you need a wideband o2 to make sure you are where you want to be (A/F ratio wise). and if you have a wide band you can do it with tuning, all you have to do is limit the range of blms 128 is 14.7, so limit the max blm to 120 and see where that gets you. if its still to lean set the max at 118, and check it again.

and dont forget about the short term blm.

someone tell me if my thinking is wrong here

 

Yes I have already tried this as mentioned before. I can make the car run at 14.0 in the cam surge areas by limiting the min blm short terms and adding fuel in the MAF table. But when I do that I have crippled the computers ability to adjust to different Iat's, Density's, Humidities etc. If the OAT changes by 10 degrees or its real humid the AFR gets skewed and I must retune.

 

Maybe doublecheck how you had the resistor was hooked up - if it was just limiting current, it might not have changed the voltage at the pcm. The pcm input might have a high impedance to not load the small signal coming from the O2 sensor. You need it hooked up as a voltage divider. You could doublecheck your circuit by measuring the voltage drop across the resistor or measuring the voltage before the resistor to gnd and after the resistor to gnd. if it isn't dropping voltage, it's hooked up wrong.

 

The WB O2 is not simply just replacing your O2 sensor, the WB will come with a device/box which requires a 12V power source. The WB cable then plugs into that box and goes to the WBO2 sensor itself installed in the exhaust pipe. Then the device/box has a programmable analog output signal which is what you would run to the factory O2 signal wire in place of the factory O2.
Here' s a link to the entire setup
http://www.innovatemotorsports.com/products/lm1.php