In a message dated 97-09-19 16:30:56 EDT, Sean Bartnik correctly corrected
me:

<<
 Actually, the oxygen sensor is a battery rather than a variable
 resistor, since it generates a voltage based on the amount of oxygen in
 the exhaust compared with the ambient air.
  >>

You learn something on this list every day!  Yes, I found the paragraph in
Probst.  Ok, Ok,  I need to recover gracefully here.  How about strapping a
couple of double A's to the exhaust with a variable resistor to the Control
Unit?  Looks like you need something on the order of one volt.

Carl