UEGO interface design expert offers help!

[Barrett Nicholas]

While out looking around the web to ensure we weren't reinventing the
wheel in our quest to design an interface for a UEGO sensor, I came
across a guy who's designed them for Ford who's willing to help us
with our design - the catch is that he's out of town this week, and
I'll be out of town part of next week. So put on your (cone-shaped)
thinking hats & lets get together the questions we need to know & I'll
condense & forward them to this guy. (I'd rather not abuse his good
will by having everyone asking him the same question ten times) If
I've understood the discussion so far,  I think the biggest obstacle
in the interface design is how to measure the impedance of the sensor
to control it's heating while not disturbing signal output - what
else?

regards,

Barrett