Other thoughts:
Leaky injector
Bad Fuel pressure regulator (rail pressure check would determine that)
TPS sensor
There are tests for all of the above situations, and specific test to determine if certain sensors are within spec.
If the CEL is popping and then going away relatively quickly, then chances are a sensor is on the verge of being bad but is "on the threshold" of being bad.
As I said above, we are flying blind until we can hopefully start with the code it is popping. Worse comes to worse, have your scanner with you and plug it in as soon as you see the code.
