William,
Your Oxygen Sensor is probably toast but check the wiring first to see if it is
connected properly. Some "mechanics" have a bad habit if disconnecting it and
forgetting to reconnect. If you have a Digitool from Darrell Boehler, you can
read off exactly what the OXS is sending to the Digifant ECU and see for
yourself if it is behaving. If you find that the OXS is dead it must be replaced
or soon your catalytic converter will burn out from the over rich fuel
condition. I know, I've been there.
-Larry

WFryer wrote:

> I wonder if anyone would have some thoughts on diagnosing a problem I have
> on my '86 Syncro.  It didn't pass emissions testing right off this year.
> Hydrocarbons were just a little over the limit at idle, but everthing was
> fine at 2500 rpm.  It passed the second time just fine with the application
> of a great amount of fuel injector cleaner.  A mechanic checked it over
> otherwise and said that it all looked fine, but that I must have gotten some
> crappy fuel.  I've run more injector cleaner and several tanks of premium
> through it since.  But it still isn't right because it smells bad at idle.
> It seems to run fine otherwise, and gas mileage is as good as it gets (19+
> in town, 20+ on the highway).  But it stinks at idle of unburned fuel - not
> sulphur dioxide).  Sort of like a propane-powered engine.   Any advice?