I know on GM cars (I know, apples/oranges) the PCM only occasionally references MAP values to determine WOT air/fuel ratio and to error check the mass airflow sensor.
Either way, it's usually the dumbest little sensors that cause the most problems, and usually don't throw codes until you're at wits end. I had a 1999 Jeep Cherokee that had serious surging and stalling issues that I chased for months. Then one day, the Check Engine light popped on and I had it scanned. Came back to the front O2 sensor. Changed that sucker out, and never had another problem.
I'm glad to read that you got it fixed.