Alright guys important update. I used field service mode and driving it was constantly perfect, equal between on and off flashes same duration.
Excellent! Solid feedback.
The only issue I noticed is after a second of sitting or going extremely slow, even after driving on the parkway, it immediately drops into open loop. Is there any concern with that or is it alright atleast for now to have that happen??
That's how others have said that the unheated (1-wire) O2 sensors operate, so this is expected
behavior, not a sign of having purchased a bad actor O2 sensor. I think Schurkey mentioned in
another thread that his single wire O2 sensor would do the same thing while waiting at a light, but
it would return to Closed Loop operation before clearing the intersection afterwards? But at the
same time others have upgraded to a heated '3-wire' O2 sensor as Stowburb (reply #12) and
PlayingWithTBI (reply #18) mentioned.
In response to another forum member expressing an interest in upgrading to a 3-wire O2 and using
the factory wiring method, I responded with the TBI-era factory wiring diagrams for the 4.3L which
went heated O2 in '94. (
Heated O2 wiring) Probably not a huge upgrade priority for you given your
newly installed & properly operating O2 sensor, but something to keep in the back of your mind down the road.
Tomorrow I will shut the cutout and see in the morning if it pops code 32 (Ill try my best to meet the parameters to engage the ecm EGR test) later on in the afternoon I will drive again with the cutout shut in the field service mode and see fuel mixture with higher back pressure and see if it still drops into open loop at stops with more backpressure.
Good stuff! BTW, thanks for sharing what you are observing. This is something that we can refer back to if
helping others who can't get their Closed Loop to oscillate just above/just below the stoich level as it is
designed to do.
Safe travels --