FC 45

[Todd....!!]

I noticed that David mentioned C3, I assume that's some kinda Vette
he's/you're talkin about?

Thanks!

Todd....!!

------------

David A. Cooley wrote:
> 
> >
> > That's interesting.  I had a bad O2 on my GN last year
> > which caused me to fail the emissions check.  I replaced
> > it with a Bosch and with a little tuning, I was able to
> > get my emissions down to 6 pmm of HC. Max allowable is
> > 220 ppm.  Before the sensor change it blew something
> > like 330 ppm.
> >
> > Maybe the Bosch sensors work fine on the older C3 ECMs
> > but not the newer P4s ?
> 
> It's the 3 and 4 wire heated O2's that have the problem... The 3 lead, they
> ground the heater to the shell, but the units where the O2 sensing element
> has 2 wires coming out is the problem child.  GM expects the low side to be
> tied to the shell and bosch isolates it.