Transmission Problem
Could be something like readings from a ported MAF or MAF ends installed. If you have a TC, it could be torque management kicking in.
Is it possible that the pan filter is positioned too close to the pan and not allowing enough fluid to get by?
I'm just trying to eliminate all of the possiblities, this is a pretty weird symptom.

The '01's and '02's usually aren't as susceptible to MAF fluctuations as the older years, but it may still be a possiblity? I would look to tuning as a last resort though after making sure there isn't a mechanical problem.

