First off I searched and couldn't find any info.
I got my DIY WBO2 up and running tonight however I am a little confused. After the warm up is complete(<1min), I am getting a free air voltage of around 3.80 volts. I put the sensor in the exhaust and I was seeing cold idle readings of 3.10-2.70 volts. This is pretty far off. Can anyone help me out or point me in the right direction.

 

While going through the checkout I could not get the same results as step 42, I had the 2.5 volts and when I closed the switch it dropped down to around .4-.3 volts and never rose. Is there something wrong here that would cause my problem?

 

The free air voltage of 3.8 is OK. A little lower then like to be seen, but still works. The step 42 that you are having trouble with isn't a fully valid check. If it works then good, if it doesn't work it doesn't matter. It is based on an OpAmp having an offset bias. IOW, something that may or may not exist.

The idle of 3.10-2.70 volts isn't correct. That would be 17 to >20 AFR. Then engine wouldn't be running if that were true. Was the sensor mounted in the exhaust pipe prior to the cat? And no exhaust leaks prior to and shortly after the senosr?

RBob.

 

I removed my cat and placed the wbo2 in that pipe. I will double check for exaust leaks. could a small pin hole cause problems? I think I might have a small leak in a weld. Thanks for your help.

 

I played around with it today and I found that if I unhook the cal resistor I get free air voltage of 4.0-4.02 would I be better off just leaving it unhooked?
When I get a chance I am going to raise the car up and put the wb in where the nb is so I can eliminate the possibility of exhaust leaks.