Some theories

[Bruce Plecan]

There are some big fibs being told, by the ecms.

This whole topic about the O2 has me thinking about something I
saw.  That the egr calculations are done against vacuum.  How can
that be, since it's just MAP that's measured.   Then this item about the
WOT, and the in car driving down the road barometric pressure
recalculation.  Pay real close attention when driving a 747 and at
slightly more than a little accleration, say just enough to extend the
shift to over 4000 rpm you can feel it happen,  least I think that
when it happens.

   Then I'll bet ya dollars to donuts the universal prom reading editing
program just uses different file extensions to make the change.
GM specific, here.

Then last night was doddling with the bench 730 ecm, and while
wired up as a MAP it was doing MAF/MAP calculations,  both
numbers seemed real.  So for the moment and till I see other
wise, I think the whole MAP/MAF issue is dead, at least in my
book, as far a better calculations.

Cheers
Bruce