[V8] Oxygen sensor.

dsaad at icehouse.net dsaad at icehouse.net
Fri Jan 30 13:50:40 EST 2004


Bosch owns the patent I believe, and ford motorcraft sensors have bosch along 
with bosch part numbers stamped right on them.

Near as I can tell, there are only subtle differences in any of these type 
sensors. eg: there may be calibrations slightly above or below stoich that a 
manufacturer may want for some reason.
There are other designs that would not work at all - eg: wideband sensors, but 
all the basic bosch designs switch right around a stoich mixture - something 
like 14.2 to 1. The output is a non-linear voltage that is of little use to the 
ECU once it is out of its narrow band. I think the usual switchover voltage is 
about 0.7 volts. 
Just for the sake of illustration here, say that the usable voltage range is 
0.6 to 0.8 volts. Anything outside that range is not an accurate measurement of 
mixture. All the ECU knows in that case is "too rich" or "too lean". The ECU 
can then only make incremental adjustments until things fall back in range.
I believe it is this process that makes the V8 ECU do its famous surge. The 
software in control of adjusting mixture reacts too quickly and constantly 
over/under shoots the target if the O2 sensor is not operating perfectly.

More than you want to know??

Dave



Quoting "Buchholz, Steven" <Steven.Buchholz at kla-tencor.com>:

> > Final comment ... I got a non-Bosch 3-wire universal OXS from 
> > my BiL's FLAPS a while back and installed it on #344.  
> > Overall I'd say that it works OK, but there is a point a 
> > couple of minutes after a cold start where the engine runs 
> > poorly for 15 seconds or so ... I suspect this to be due to 
> > the ECU thinking the OXS is warmed up when in fact it has not 
> > yet ... I will not install another OXS in the car that is not 
> > made by Bosch and have the same general design as the 
> > standard part ...
> > 
> ... sorry about the follow on ... I had intended to mention that I'm
> pretty
> sure the replacement part was branded "Motorcraft" ... so I suspect that
> at
> least some Ford replacement parts may be the same design ...
> 
> Steve B.
> San Jose, Kaleefohnia (USA)
> _______________________________________________
> V8 mailing list
> V8 at audifans.com
> http://www.audifans.com/mailman/listinfo/v8
> 


More information about the V8 mailing list