'96 Ford Probe won't smog due to lack of engine codes...

hi folks,

i have a 1996 2.0 liter 4 cylinder Ford Probe that will not pass
California smog because the computer is not storing any codes. it
passes the actual emissions tests with flying colors, the problem is
that the smog tech needs to see that the computer has gone through a
complete "drive cycle", otherwise it automatically fails the overall
test. about a month ago i had the air density sensor replaced and at
that point the computer was reset. the mechanic told me i needed to
drive for about 100 miles, at various speeds (around town and freeway)
and that should acccomplish the "drive cycle" and allow me to smog it.
well over a month later and about 700 miles it still won't smog due to
a lack of engine codes. the smog tech said it didn't have one single
code on the computer.

i have taken it to the Ford dealer repair shop (yeah i am going to get
gouged), and they seem to be stumped as well.

anybody ever heard of something like this or offer any advice? i really
like the car, and it runs superb, but that isn't helping with the smog
and registration.

should i take it to a Mazda shop instead (the engine and chassis are
actually Mazda)? any suggestions would be greatly appreciated.