I read a bunch of good stuff in the archives about O2 switching voltages. I think I understand that if you change the R/L, and mean O2 voltages you will change the calc'd AFR. So I can make closed loop AFR more rich by raising the voltages.

My question is will this change the BLM in any way? My first assumption is to say no. Because it is delivering more fuel because you told it to, and now it thinks that the higher O2 voltage is correct.

I remember Grumpy saying stick with the GM O2 sensors because some aftermarket units were not accurate...or something to that effect. Is there any way to determine the switching point of an O2 sensor?

 

The cross over vary a little, ie from .44 to .5.

Just run closed loop and dial in what ever AFR you want for whatever condition you want.
Having a WB makes the above real easy.

Changing the *swing* voltages will slightly change the AFR, but not as much as you might expect. Raising the lower one seemed to help some. Keeps the ecm from swing SO far lean.

It's Bosch that was selling guestionable sensors.

Standard useage claim of for off road use, only.

 

I think Grumpy meant to say open loop, not closed. With open loop the O2 sensor is out of the equation.

RBob.

 

It's something I added to the ecu file I just uploaded but haven't gotten a chance to play with. Do you think the heated Bosch sensors are bad or is it just the standard replacement single wires that had a bad (big) batch? I'm running with a 3 wire Bosch, in general, do the heated o2 sensors swing faster so you can narrow the range?

 

I wonder the same thing JPrevost. I also took a look at the ANLU cop car bin. I noticed that the O2 voltages are around 550 mV. That's very intersting because my stock settings (was ASDU) are 407 mV.

I'm also running a 3 wire Bosch.